PEBIPATUS GUIANENSIS. 145

On Peripatus guianensis (sp. nov.).

Richard Evans, M.A., D.Sc.(Oxon.),Curator of the Museum, Georgetown, British Guiana.

With Plates 13 and 14.

CONTENTS.PAGE

Introduction . . . . . . 145External Characters . . . . . 149Internal Characters . . . . . . 1 5 3

Male Generative System . . . . . 153

Female Generative System . . . . . 154

Summary of Characters . . . . . 154

Concluding Remarks . . . . . 155

Explanation of Plates . . . . . 159

INTROOTTCTION.

To add another species to the already somewhat largenumber of the New World members of the family Peripatidaewill probably seem to many zoologists to be unwarrantedpresumption, for within the last few years the number ofspecies from this part of the world has been more thandoubled—a result, to some extent, of redescribing old materialrather than of discovering new forms. However, the speciesunder consideration in the present paper cannot be identifiedwith any of the already known ones; and whatever view wechoose to adopt regarding the validity of some of the specieswhich have been made, I am of opinion that no one will doubt,

VOL. 4 7 , PART 2.—NEW SEEIES. K

146 • RICHARD EVANS.

after perusal of the facts which will be recorded in the comingpages, that Peripatus guianensis is a new species.

Perhaps, before proceeding to the actual description, itwould not be out of place to refer to the utter uselessness ofmuch that has been written on the Peripatidae, especiallyas regards the colour and dimensions of preserved specimens.In the first place, observations made on the colour of speci-mens preserved in either alcohol or formalin have little orno value. The colouring matter existing in the skin ofthe neotropical Peripatidas is gradually abstracted by theabove-mentioned reagents, and the characteristic markingsand patterns, when such exist, disappear in a few days.Ultimately the animal becomes quite colourless, the colouringmatter being dissolved in the preserving liquid, and giving it.a more or less brownish tint. Unfortunately this is only tootrue of P. guianensis, which is the subject of the presentpaper. After the specimens had been in either spirit orformalin for a few days the characteristic markings haddisappeared so completely that no one would have suspectedthe presence of two distinct species among the specimens inmy possession, unless he took into consideration some characterother than the coloration, although in the living animal thedistinctive markings of P. guianensis were so evident thatthe black man who collected the specimens for me was ableat a glance to separate the individuals belonging to tinsspecies from those of the other species found in Demerara.In consequence, I have been forced to the conclusion thatobservations made on the coloration of neotropical forms ofthe Peripatidte, to be of any value, must be made on theliving animal.

In the second place it is fashionable, in describing a newspecies or in redescribing an old one, to give the exact dimen-sions of the specimens. The length, depth, and width of theanimal are carefully recorded, and very often tabulated; thelength of the antennae and the distance between the succes-sive pairs of legs are observed with great care, but all to nopurpose, save to show that the author is capable of paying

PBRIPATUS GDTANENSIS. 147

minute attention to details, however small and insignificantthey may be. Such measurements are not only useless, butthey are positively harmful, for they are unconsciously beingused as characters having considerable specific value, althoughit is absolutely clear that from the point of view in questionthey are of no importance. To arrive at this conclusion thereis no need but to consider the fact that in any collectionconsisting of a fair number of individuals of a particularspecies there are specimens the dimensions of which are atleast three times that of the smallest ones, although the latterare as perfect as the former from the structural point of view.The dimensions of any individual specimen depend on theage of the animal at the time it was killed, and consequentlyhave no specific value. Again, the dimensions of a deadP e r i p a t u s , to a great extent, depend on the method adoptedto kill the animal. Owing to the presence of circular,longitudinal, and oblique muscles in the body-wall, a P e r i -p a t u s measuring, when alive, about 80 mm. in length, iscapable, at death, of contracting itself to about 50, or even40 mm. The amount of contraction taking place varies withthe reagent used, as well as with the degree of concentrationof that reagent. Consequently the dimensions of a deadP e r i p a t u s , when given in a paper, do not increase the valueof tho account, for they have no constant relation to the sizeof the living animal, the length, depth, and width of whichvary according to the age of the individual under considera-tion .

In the third place, whether the legs are long and slenderor short and stumpy, and whether the successive pairs aresituated at a distance from or close to each other, are pointsof no importance in a dead specimen; nevertheless they areearefully observed and recorded. If the specimen diesfully extended the chances are that the legs are also fullyextended, and, in consequence, are long and slender, andplaced at a distance from one another; but if the specimendies in a contracted condition the chances are equally infavour of the legs being contracted, and, in consequence, of

148 RICHARD EVANS.

their being short and stumpy, and placed close to one another.Hence the facts recorded as to the shape and relative positionof the legs in a dead P e r i p a t u s have no practical value.Because the usually recorded facts as to the coloration and thedimensions of preserved specimens have no value, in thepresent paper the reader will look in vain for the facts inquestion.

The material to be described in the coming pages wascollected for me by a black man aback of a plantation situatedon the east bank of the i*iver Demerara. The specimenswere collected during the first half of August, 1902, and con-sisted in all of nine individuals, which were distributedbetween the sexes in the ratio of eight females to one male.This fact is in accordance with the almost invariable rule thatin any collection of P e r i p a t u s the females are more numer-ous than the males.

In looking at this small collection of nine animals the ideathat occurred to me at first was that I had been so fortunateas to come across the male of P e r i p a t u s im-Thurmi ,which has, up to the present, remained undiscovered; but ondissecting one of the specimens I found that the animal beingexamined was a female, and I was forced to the conclusionthat I must have discovered a new species. The specimenswere found on more or less swampy ground, under the remainsof rotten leaves and dead tree trunks. Some of them werekept alive at the museum in a glass-covered box, in whichwas placed a quantity of the soil, leaves, and rotten woodwhich they usually inhabit. To all this was added enoughwater to make the contents of the box as damp as the manwho collected the specimens thought their customary habitatwas, and the result seemed to be a veritable swamp. Speci-mens belonging to another species collected in the samelocality and under similar circumstances still thrive well inthe artificia swamp described above.

PERIPATUS GUJANENSIS. 149

EXTERNAL CHARACTERS.

The Dimensions of the L iv ing Animal.—The greatestlength the male specimen seemed to be capable of, even whenin motion, was about 35 mm. The female specimens seem toconsist of individuals of all ages, ranging from a young onecontaining no embryos, and measuring about 30 mm. inlength when in motion, to older ones full of young in differ-ent stages of development, and measuring, when fully ex-tended, no less than 80 mm. in length. In proportion to theirlength they seem to be stouter than P. im-Thurm i. Theirgirth, however, depends to a considerable extent on the stateof development attained by the young which they contain.In the moving animal the legs are slender, and situated at aconsiderable distance from one another, but on contraction ofthe animal, either when irritated or at death, both the bodyand the appendages shorten and become thicker, and thespaces between the successive pairs of legs almost disappearin spite of the fact that in the living animal the width of thespaces in question is to that of the leg as seven is to five.This latter fact demonstrates in the most clear way the utterfutility of giving the dimensions of dead specimens, whichare invariably more or less contracted.

The Colour of the L iv ing Animal.—The colour variesconsiderably in tint; nevertheless the pattern is maintained.On the dorsal aspect the colour is some shade or other ofbrown, and on the ventral of grey. The variation occurringin different individuals is brought about by the presence orabsence of a pinkish constituent, which gives the animals5

colour a warmer or colder tone. The mid-dorsal position isoccupied by a chocolate-coloured line of a decidedly darktint, with lozenge-shaped areas roughly corresponding to theappendages arranged on it. Smaller areas of a similar shapemay be intercalated so as, to some extent, to interfere withthe apparently segmental arrangement of the bigger ones.On either side of the line in question is found a zigzag one

loQ . KIOHAED EVANS..:

much lighter in tint and warmer in tone than either themedian line and its lozenge-shaped areas or the flanks of theanimal. The sides of the animal agree in tint with the mediandorsal line, but become somewhat lighter in the immediateneighbourhood of the walking appendages. The ventralsurface is grey in colour, but with a pinkish constituent insome individuals. The spots corresponding to the •ventralorgans, and situated mid-ventrally between the appendages,are always a lighter grey. In the majority of cases theantennae are somewhat darker than the dorsal surface. Thedarker and lighter areas on the dorsal aspect are producedby a corresponding difference in the colour of the papillae,which are dark brown in one case and light brown in theother.

The Skin, with its Ridges and Papilla.—The skin isthrown into folds or ridges, on which the papillae, bothprimary and accessory, are situated. In the mid-region ofthe body there are about twelve folds to every pair ofappendages. As a rule, seven of these pass uninterruptedlyfrom the mid-dorsal line over the sides and between theappendages to the ventral surface. Of the remaining folds,at least two terminate about halfway between the mid-dorsalline and the-legs, while the other three reach the appendagesand there end. The continuity of the folds is broken at themid-dorsal position by a very narrow and clear line, which isvisible only with the microscope. - On either side of the linein question, in the spaces between the folds, the openings ofthe trachea) are situated. • • - - .

On the dorsal aspect of the head the papilltB present adiffused arrangement. Around the base of each antennathey are arranged in three or four more or less completerings, on one of which the eye is situated. < The -rings inquestion pass between the antennae, and those on either sideare not separated by a row of papillte passing from the areaon top of the head, on which the papillae are irregularlyarranged, to a similar area situated on the ventral surface in.front of the mouth. ... . ' . . . . . . . .

PERIPATUS GUFANENSIS. 151

. On -the folds of the skin two kinds of papillae are found :first, the primary papillte, large in size, and differentiated toapical and basal portions; and secondly, the accessory papillae,smaller in size and undifferentiated. As a rule, the basalportion of the primary papilla) slopes very gradually, andhas an extensive outline which stretches across the entirefold (PI. 14, figs. 1 and 2). The basal outline of the primarypapillae is far more distinct near the mid-dorsal line than itis lower down on the sides vyhere the bases of the papilla)run into one another. On the limbs the basal portion mayassume an almost cylindrical form. The apical portion whenfully extended is almost invariably cylindrical in shape, andcarries a spine on its top. The basal portion is covered byshort broad scales, but the apical one by long narrow ones;The accessory papillee present a considerable amount ofvariation, according to the position which they occupy.Near the mid-dorsal line they stretch across the entire fold,and, as a rale, only one is found between the primary papillas(PI. 14, fig. 1); but near the appendages they are small, anddo not cover the fold from side to side, for several of themoccupy the space between the primary papillte (PI. 14, fig. 2).It seems that the accessory papilla) situated on the sideshave been produced by the breaking up of larger ones,similar to those found in the vicinity of the mid-dorsal line.

The Mouth.—The mouth has the usual shape and posi-tion, and is surrounded by large papillse which are yellowishwhite in colour. Half a dozen of these papilla: form ahorseshoe, situated in front of the mouth, the remainderbeing disposed in a ring outside. When the mouth is in acontracted condition the complete ring seems to be inside,and the horseshoe outside. The appearance the papilla)surrounding the mouth present depends on the degree ofcontraction.

The Genital Aperture.—This opening is situated be-tween the penultimate pair of appendages, and is surroundedby papillae which are slightly enlarged. In some of thespecimens the area round the genital aperture is raised, so

152 RICHARD EVANS.

that the actual opening is placed on top of a conicalelevation.

The Antennas.—Immediately behind the antennas thepapillas on the head are arranged in three or four more orless complete rings, on the second of which, counting from infront, the eye is situated. The base of the antenna, con-sisting of two segments carrying the usual papillas, is followedby a third segment, on which the scales are arranged in quitea simple and unmodified way. The segment in question isfollowed by forty-two others similar in character to the firsttwo. Thus the whole antenna consists of at least forty-fivesegments.

The Jaws.—The two blades of the jaws present the samestructure as they do in most neotropical species. The outerblade has one big tooth, on the inner side of which is situateda small denticle. The inner blade has a large tooth, on theinner side of which is a small denticle followed by a diastema,in which a vestige of a second denticle may be seen. A rowof ten or eleven small denticles occurs on the inner side of thediastema.

The Oral Papillas.—These organs have the same struc-ture as in other South American forms, and call for nofurther remarks.

The Walking Appendages.—The number of walkingappendages present vary from twenty-four to twenty-eightpairs. The single male specimen in my possession has onlytwenty-four pairs, one of the females has twenty-seven pairs,the remaining seven specimens being possessed of twenty-eight. The appendages carry four spinous pads, and onthose situated in the mid-region of the body there may bea small remnant of a fifth. Bach leg of the last pair hasonly two pads, which are somewhat reduced in size. Of thelegs of the penultimate pair each one carries three pads.The coxal organs are well developed, but in the majority ofcases they are retracted so as to present the appearance ofgrooves. The renal apertures are situated on the inner sideof the coxal organs, with the exception of those of the fourth

PEB1PATUS GU1ANEN8IS. 153

and fifth pairs of legs, on which they are placed between thethird and fourth spinous pads on the top of a papilla (PI. 14,fig. 5). In the male, sexual papillse are found on the anti-penultimate pair of legs (PI. 14, fig. 6).

The feet present the same general appearance as in themajority of American species. There are two primarypapillae in front of the distal end of the foot and one behind.On the ventral aspect of the foot there are two pairs ofelevations, on every one of which there are three spines,twelve in all, which is the maximum, but not the minimumnumber of spines observed on any foot. In the cases inwhich there were fewer spines than twelve some of them hadprobably been lost.

The number of appendages present in several embryos, inwhich all the legs had already appeared, have been counted,and have been found to vary from twenty-four to twenty-eight pairs, numbers which represent the extremes found inthe adults. It seems highly probable that specimens withfewer than twenty-four or with more than twenty-eight pairswill prove to be rare exceptions in P e r i p a t u s g u i a n -

INTEKNAL CHAKACTERS.

As far as I have been able to make oat from dissection,the iuternal anatomy agrees with that of the most typical ofthe neotropical species, and there is no need but to point outthat certain organs of importance do exist. The alimentarytract is quite normal, and is surrounded by the numerousbranches of the slime glands, which extend almost to theposterior end of the animal. The organs which demandspecial notice are those which constitute the male and femalegenerative systems.

The Male G e n e r a t i v e System.—The male generativeorgans are quite typical of those of the South AmericanPeripatidae (PI. 14, fig. 9). The testes are tubular in form,and are freely suspended in the body-cavity. Each testis

154 itlOHAKD EVANS.

communicates with a seminal vesicle which is oval in shape,and debouches into a vas deferens (PI. 14, fig. 9, v. d.). Theright yas deferens passes backwards and, after a short course,crosses to the left side, passing under the ductus ejacula-torius in doing so. Having crossed over it unites with itsfellow to form the common duct, which is coiled on the leftside of the intestinal tract, and which ends in the ductusejaculatorius (PI. 14, fig. 9, e. j . d.). Fig. 9 on Plate 14 showsthe male generative organs magnified about four times linear,and considerably displaced to show the parts. The male alsopossesses a pair of male accessory glands, which extend asfar forwards as the twenty-first pair of legs (fig. 9, m. a. g.).

The Female Generative System.—The female genera-tive organs are typical of those of the species found in SouthAmerica (PI. 14, figs. 10 and 11). The ovary is small, and isattached to the floor of the pericardium in the region of thetwenty-fifth pair of legs in specimens possessing twenty-eightpairs (fig. 10). The ova are small and endogenous. There isa pair of receptacula ovorum, the end sacs of which aresmall, and communicate with the funnel by a constricted neck(PL 14, fig. 11, re.o.). The receptacula seminis are welldeveloped, oval in shape, and may be easily seen with thenaked eye (fig. 11, ru.s.). The uteri pass forward so as toform two ascending limbs, which on turning back form thedescending ones, which end in an extremely short vagina(fig. 10, ut.). In the pregnant female the uteri containembryos in all stages of development, ranging from thesegmentation stages to young individuals possessing all thecharacters of the adult, save that they are lighter in colour.

SUMMARY OF CHARACTERS.

1. Six of the females are larger in size than the male.2. The male specimen has twenty-four pairs of appendages.3. One female has twenty-seven pairs of appendages, while

the other seven have twenty-eight..4,.The renal apertures of the fourth and fifth pairs of legs

PERIPATUS GUIANENS1S. Io5

are placed on top of a papilla situated between the third andfourth spinous pads.

5. The papillae situated near the mid-dorsal line are large,and stand on a base line which is almost rectangular.Principal papillae alternate almost regularly with accessorypapillse. On the flanks the latter become broken up intoseveral small ones, which occupy the spaces between theprimary papiH.93.

6. The female is possessed of receptacula seininis andovorum.

7. The ova are small, devoid of yolk, and endogenous.8. The embryos in the uteri are in successive stages of

development.9. The male has an elongated common duct, and on the

twenty-second pair of legs has two pairs of sexual papillte. .10. The outer blade of the jaw has one accessory tooth.11. The inner blade of the jaw has one accessory tooth,

followed by a diastema and a row of ten or eleven denticles.

CONCLUDING RMMAEKS.

On. referring to Mr. Sedgwick's monograph on the Peri-patidas we find that he examined fourteen specimens col-lected by Mr. Sclater in the Pomeroon. Of these fourteenspecimens he states that seven had thirty pairs of appendages,six had thirty-one, and one had twenty-seven. Out ofthirteen embryos examined seven had thirty pairs and sixhad thirty-one. Of the. four embryos taken from the onewith twenty-seven pairs, three had twenty-seven and one hadtwenty-eight. In a foot-note, though not regarding it asprobable^ Mr. Sedgwick admits that the specimens with thirtypairs may be .specifically distinct from those with twenty-seven and those with thirty-one.1 In consequence of thisuncertainty he included all the-specimens under one specific

. ' " A Monograph on the Species and Distribution of the Genus Penpal us(Guilding)," 'Quart. Journ. Micr. Sci.,' vol. xxviii, N.S., pp. 431—494pla. 34,-4(L. . . . . . . . . . . . .

156 RICHARD EVANS.

name, Demeraranus, though Mr. Sclater had previouslygiven the same specimens (in part, at least) the name im-Thurmi.1 If Mr. Sedgwick had followed a middle course,and had arrived at the conclusion that he had two speciesamong the fourteen specimens which he examined, it wouldseem that he would have been nearer the truth than he wasin the supposition that he might have three, or in the con-clusion which he adopted, that he had only one. This viewis supported by the following facts :—In the first place, outof the specimens possessing thirty or thirty-one pairs ofappendages, Mr. Sedgwick obtained embryos with eitherthirty or thirty-one pairs, but out of the one with twenty-seven pairs he took embryos with either twenty-seven orWenty-eight pairs. In the second place, Mr. Sedgwickcounted the number of appendages in no less than thirty-onespecimens, both embryos and adults, and yet not a singlespecimen was found possessing twenty-nine pairs, which is avery curious fact if all the specimens belonged to one species.In the third place, all the fourteen specimens examined byMr. Sedgwick were females, and consequently not likely tobelong to one species. If the specimen with twenty-sevenpairs of appendages had been a male, Mr. Sedgwick's viewthat he had only one species would not have been so im-probable, as the males often have fewer appendages than thefemales. It may be fairly concluded that Mr. Sedgwick hadamong his fourteen specimens the representatives of twospecies; and, further, it is possible that if he had been writinghis monograph to-day, instead of twenty years ago, he wouldhave adopted a different view.

M. Bouvier,2 in his review of the American Peripatidse,does not raise the question here considered, and adopts Mr.Sclater's name (im-Thurmi) in preference to that of Mr.Sedgwick (Demeraranus).

1 "On the Early Stages of the Development of a South American Speciesof Per ipa tus ," 'Quart. Journ. Micr. Sci.,' vol. xxviii, pp. 343—361,pi. 24.

5 'Aim. de la Soc. Eutouiol. de France,' vol. lxviii, 1899, pis. ii—vii.

PBRIPATUS GUIANENSIS. 157

That there are two species of Per i pa t us inhabiting theeast bank of the river Demerara is an indubitable fact;namely, P. gu ianens i s , with from twenty-four to twenty-eight pairs of walking appendages, and another species withthirty-one or thirty-two pairs. No males of the latter specieshaving been discovered, it is impossible to say how manypairs of appendages they possess, but as regards the femalesit may be stated that, on an average, five out of every sixhave thirty-one pairs, the remaining one being provided withthirty-two. Although over sixty specimens were examined,the majority of which were young, born in captivity, not oneof them was possessed of only thirty pairs of legs. If it betaken as proved that there are two species inhabiting thePomeroon, the question whether these two species are respec-tively the same as those found on the east bank of the riverDemerara immediately suggests itself.

In the first place, do the specimens with thirty-one orthirty-two pairs of appendages from the Demerara belong tothe same species as those with thirty or thirty-one pairsbrought from the Pomeroon and examined by Mr. Sclater andby Mr. Sedgwick ? This is a most difficult question to answer,as at present I have no material in hand from the Pomeroon.On the one hand, if we judge from the descriptions andfigures given of P. im-Thurmi , we should have no hesitationwhatever in answering this question in the affirmative; but,on the other hand, we must take into consideration the verysignificant fact of the discrepancy in the number of append-ages. Among thirteen specimens of P. im-Thurmi exa-mined by Mr. Sedgwick, seven had only thirty pairs ofappendages, six had thirty-one, but none had thirty-two.Among sixty specimens from the Demerara examined by mefifty had thirty-one pairs of appendages, ten had thirty-two,but none had only thirty. In my opinion the complete lackof specimens with only thirty pairs of appendages from theDemerara, and of any with thirty-two pairs from the Pomeroon,are most significant facts, and incline me to believe that theanimals under consideration form two distinct species.

158 EICHARD EVANS.

In the second place, do the specimens with from twenty-four to twenty-eight pairs of appendages (P. gu ianens i s )from the Demerara belong to the same species as theindividual with twenty-seven pairs from the Pomeroonreferred by Mr. Sedgwick to P. d e m e r a r a n u s (P. im-Thurmi , Sclater) ? Although the supposition that thematerial from these two localities mentioned in the abovequestion belongs to the same species seems legitimate, I donot consider it very probable. In discussing this question itshould be remembered that Mr. Sedgwick saw Mr. Sclater'sspecimens alive, opened them, and took the embryos out ofthem; and although he was "unable to make a detailedexamination of them in the fresh state," I am fully convincedthat if the individual possessing only twenty-seven pairs ofappendages had displayed the same characteristic markingsas P. g u i a n e n s i s does, he would have immediately detectedthe difference between it and the remaining nineteen speci-mens of the collection in question. The most likely viewseems to be that Mr. Sedgwick examined two species whichcould not be distinguished from each other with the nakedeye, unless the appendages were counted a feature, to which,at that time, no great importance was attached. It is un-fortunate that so little is known of the structure of thespecimen possessing* twenty-seven pairs of appendages fromthe Pomeroon, and the only correct attitude, until a furthersupply from that district shall have been collected, is tosuspend judgment. Owing to this uncertainty I prefer usinga new name, gu ianens i s , to adopting the invalidated one,d e m e r a r a n u s , for the new species described in the presentpaper.

PERIPATCJS GUTANENSTS. 159

EXPLANATION OF PLATES 13 & 14,

Illustrating Mr. Richard Evans' paper on " Feripatusguianensis (sp. nov.)."

REFEBENCE LETTERS.

ej. d. Ejaculatory duct, m.a.g. Male accessory gland, m.d.l. Mid-dorsal line, ov. Ovary, p.p. Primary papilla, re. o. Receptaculuiii ovbrum.re. s. Receptaculum seminis. s. p. Secondary papilla. Is. Testis. id.Uterus, v. d. Vas deferens. v. s. Vesicula seminalis.

PLATE 13.

The figure on this plate represents one of the biggest of the femalespecimens. It measured about 80 mm. in length when in motion.

PLATE 14.

FIG. 1.—This figure represents a portion of the skin situated on either sideof the clear line which occupies the mid.dorsal position. The large primarypapillae (p.p.) alternate with the almost equally large secondary papillae (s.p.).The apical piece of the primary papillae is not represented. Note the trachealopenings situated on either side of the clear line and between the folds of theskin.

FIG. 2.—This figure represents a portion of the skin from a position closeto one of the appendages. The primary papillee (p.p.) lack the sharp basaloutline of those shown in the first figure, and the secondary papillte (s. p.) arefar more numerous and smaller than those shown in the first figure, a resultbrought about probably by the breaking up of the latter.

PIG. 3.—This figure illustrates the inner blade of the jaw.FIG. 4.—This figure illustrates the outer blade of the jaw.FIG. 5.—This figure represents the fourth leg of the left side. Note the

position of the renal papilla between the third and fourth spinous pads, andthat it is quite clear of both of them.

FIG. 6,—This figure represents the twenty-second walking appendage onthe right side of the male type specimen. Note the two large sexual papilla?situated on the postero-ventral aspect of the proximal end.

The fiflh and sixth figures should be compared, because they incidentally

160 KICHARD EVANS.

happen to illustrate the difference in appearance existing between a contractedand a non-contracted appendage.

FIG. 7.—This figure shows the structure of the foot. There are twoprimary papillae on the anterior aspect, but only one on the posterior. Onthe ventral aspect there are two pairs of elevations, every elevation carryingthree spines, which is the maximum number that was observed.

FIG. 8.—This figure shows a primary papilla from a position midwaybetween the appendages and the mid-dorsal line.

FIG. 9.—This figure represents the posterior end of the male type specimendissected from the ventral surface. It shows the male generative system,consisting of two tubular testes (is.), two oval-shaped vesiculse seminales(v. s.), two short vasa deferentia (u. d.), and a long and coiled ejaculatory duct(ej. d.), together witli a pair of male accessory glands (m. a. g.).

FIG. 10.—This figure represents the posterior end of the female typespecimen dissected from the ventral surface. It shows the female generativeorgans, consisting of an elongated ovary attached to the floor of the peri-cardium by a fine cord, receptacula scminis and ovorum, and two uteri (id.),which contain young in different stages of development.

FIG. 11.—This figure illustrates the ovary (ov.), the receptacula ovorum(re. o.), the receptacula seminis (re. s.), and the commencement of the uteri(ul.) of the female.

%t. A 7,MS.M.lc

Hath,Lithr London.

Hut:.,Liltf London.