122 PROF. G . B. HOWES ON THE AZYGOS [Feb. 21,

I n June last Major Cassel presented to the Society two Trap-door Spiders from Natal. These are still living, but up to Saturday last I had not seen either of them ont of their cells; on that day I, after some trouble, got one out, and, as well as I was able, made a sketch of it.

I wrote to the Rev. 0. P. Cambridge respecting these Spiders, asking him if he could tell me anything about them ; he replied, saying, that he ‘‘ confidently expected the S.-ilfrican Trapdoor Spiders would be new to science, as he did not, a t that moment, re- member anything of the kind of the size I mentioned.”

Tlrese Spiders have fed principally upon Cockroaches, and the one I had out on Saturday was in splendid condition.

The following papers were read :-

1. Note on the Azygos Veins ill the Anurous Amphibia. By.G. B. HOWES, F.Z.S., F.L.S., Assistant Professor of Zoology, Normal Sch. of ,Science and R. Sch. of Mines.

[Received February 7, lES8.1

I t is customary to regard the presence of the vena cava inferior as a special characteristic of the air-breathing Vertebrata, and the view mast generally accepted and taught holds this vessel to be a late development, which replaces the posterior-cardinal veins of fishes. Indeed, some authorities would regard its presence and absence as distinctive of the air-breathiiig anti water-breathing series respec- tively. Balfmr wrote of it’:--“The venous system of Amphibia and A.mniota always differs from that of fishes in the presence of a new vessel, the vena cava inferior, which replaces the posterior car- dinal veins, the latter oiily being present, in their piscine form, during embryonic life.”

Chief amongst recent researches into the morphology arid develop- ment of the venons syst.em are those of Parker ’ 3, Hochstetter s, Meyere. The work of the second-named author will become little short of revolutionarv, should his deductions hold good. He claims, as the chief result of his investigations, to have shown that the vena cava inferior, instead of being throughout its whole extent a primarily independent vessel, is a compound structureb-the product of a fusion

1 Comp. Embryology, pol. ii. p. 538. a “ On the Venous System of the Skate,’’ Trans. New-Zealand Instit. vol. xi.

1580, p. 49. ‘‘ On the Blood-vessels or Mustel~us antarcticus,” Phil. Trans. vol. 177. 1556,

p. 655. 4 “ Beitr. ziir vergleichend. Anat. und Entwickluirgsgesch. cl. Venensyst. der

5 “ Ueb. die Bildung d. hinteren Hohlvene b. cl. Siugethieren,” Anat. Anzeiger,

“ Ueb. d. Entwir:kluug drs Herzens uiid d. grossen Gefassstimme b. d. Sela

Amphib. uncl FiscLe,” Morpholog. Jabrb. vol. xiii. 1SS7, p. 119.

vol. ii. I S S T , p. 517.

cliicrlr.” N;~ples Mittlreilwipcn, v o l . vii. 18x7, p. 335. I

1888.1 VEINS I N THE ANUROUS A M P H I B I A . 123

between a late-formed hepatic vessel and one or both of the posterior cardinal veins. To that portion which is derived from the cardinal veins, and which receives the venae renales revehentes, he applies the term “ urniere Abscilnitte”; it is represented, in the adults of the higher forms, hy all behind and including the renal reins. IIe further asserts that whereas i n Amphihia the two posterior cardinals become confluent to form this, in Mnmmalia’, on the other hand, the cardinal vein of the right side also gives origin to it.

On the completion of the above-named developmental processes the anterior or prereiial portions of the posterior cardinal vciiis eitlier become modified, to form the aeypos and hemi-amgos vcins of human anatomy, or, for the most part, disappear. Hochstettcr has worked out the steps in the development in Bombznator, Pelobates, Rnno, and Safarnandra among Amphihia. So far as Bombinalor is coiicerneil, he fully rorifirms the classical researches of Goette, excrpt for the fact that that author failed to observe the peraisteiice of the cntire posterior cardinals in the adult. IlochLtetter hns sliown that in Bornbinator iynetrs thcir anterior portions (morphological azygos veins) not only persist for life, but that with their confluence pus- teriorly, to forin tlie hinder part of the vena cata iofrrior, tlirir oiiginal continuity is not destroyed. There thus result t n o well- defined veins (c.p. of fig.), which pass upNarCls and forwards, side by side with the arches of &he aorta, putting, as in some Urodeles, the fully formed vem cava inferior into direct communication with the veins of the anterior extremities.

In Ram, according to Hochstetter, the anterior segments of the pos- terior cardinals atrophy during metamorphosi.. An individual example of the Corninoil Frog (A?. tempos-aria, adult Q ) has, howevrr, recentlv come into my hands’, in which the vessel peisistrd f\Jr its entirety on one side (see fig., p. 124)’. Not only so, but its development had con- tinued pari passu with that of other related parts-in eacess of that seen even in Bombinutor. The drawing speaks for itself as to detail, and it must suffice to point out that, except as concerned the presence and relations of this vein, no noteworthy difference could be detected between the distribution of eten the smaller vessels in‘ this animal and those of the ordinary adult. The least nornial among the veins were the ovarian ones (ow.), which, as will be seen, were strikingly asymmetrical. There was not the remotest trace of the correspond- ing portion of the right posterior cardinal.

The persistence of this vein in one of the Kanidce is, in itself, deserving of record ; but careful coniparison with Borndinator has revealed an interesting difference between the two. IIochstetter con- firms and extends Goette’s discovery that tlie main trunks of the venze renales advehentes are primarily continuous with the posterior car- dinals, forniing trunks (Jacobso:i’s veins) the lower ends of which, subsequently receiving the iliac veins, become the renal portals

Anat. Anz vol. ii. 1667, p. 519. Thanks to the diligence of my pupil, Mr. W. F. Huiiie. A8 these sheets were pnssing tliiough the press I niet with tlie wi ic con

clitiun 111 a male of B n ~ ~ ~ h i i i c t f o r . Iinmhiiiu

124 P R O P . G . R iiowics O N n I & AZYGOS [Pel,. 21 ,

of the sdiilt. 111 UoniLinrrtor, howcter, despite the pcrsiatence o f liotli reiial portal arid azygo$ \eiirq, this co:itiiiuitv is rrriitriallp lost. In tlie specinien of'tiie Corrinroii Frog uiider coiisiderntion it p r&ted ,

1888.1 VEINS I N THE ANUROUS AMI'HIBIA. 12.5

Hochstetter has examined Bombinntor, Hyla, Rana, mid Bufo, and in none but the former has he found a persistence of the vessels above named. H e was not in a position to discuss the morpholo- gical significance of the fact, as a guide to affinity. The researches of Cope', Eonlenger', and others point to the conclusion that the Discoglossida, rather than the Aglossa, are to be regarded as the least modified of all living hnura. Boulenger writes', "in the presence of ribs and opisthoccelian vertebra the members of this very natural family closely approach the higher tailed 13atrachiaus." The retention of the posterior cardinal (az,vgos) vein i n Bi~rnbinator can only be regarded as a sign of low affinity, and, mindful of' the well-known osteological and other chixracters of this family, I have been led to examine other genera thereof, with the view of ascer- taining if this retention is common to a11 its members. I tind the veins of both sides well developed in two specimens ( d and 2 ) of Bombinator bombinus. Of five Alytes obstetricans examined (three 8 , two 9 ), four showed no traces ; in the fifth, however (a 9 ), both veins were fully represented, but small. This was also the case in a 8 of Discoylossuspictus. From this it must be assumed that the character is fairly distinctive of the Discoglossidz.

Thanks to Prof. Huxley, I have had the opportunity of examiuing adults of Pipa ( d ) and Dactyletkra ( $! ). I n neither of these could I observe a trace of the vessels in question ; the specimens had been previously very much dissected, but should subseqnent investigation upon fresh material (which I hope to carry out) substantiate this, the dedurtions of the afore-named authors as to the lowliness of the Disrogloesidze will receive striking confirmation.

'lliese facts are, in themselves, sufficient to invest any Anura uith a fresh interest, whose affinities with the Discoglossidae have been suggested or called into question. Conspicuous among such is Pelodyteu ; and for an opportunity of examining this and other genera my best thanks are due to Mr. Boulenger, who has, with his customary generositv, afforded me unstinted aid. Pelodytes is held by Giinther n n ~ l Mivart' to be allied to the Discoglossidz, and by others (Cope, Lataste, Bouleuger) to the Pelobatidae'. As I am unable to f ind any traces of the vein in two adult males of PeZodytes and one of I'elobutes, I can but give my support to the latter view.

Finally, Hochstetter, in his earlier paper, describes an anastomosis between the hepatic sinus and the posterior cardiiial veins in Elas- niobranchs', which he holds to he tantamount to the forination of a vena cava inferior. This deduction is far too revolutionary to merit immediate atloption ; the probability of its arcuracj is, however, cer-

' Nat. IIist. Review, 186.5 ; also Journ. of Acad. Nat. Sci. Philadclphia, vol. vi . 1866, 1). 67.

'' C Ltalogue of Batmcliia Salientia, British Muscuiii, 18SI. Illid. p. 444.

4 P. z. d. 18(i!l, p. "0 e t ssq. For r?ferciices, see Cat. IIitt,l*. Salicritia.

6 (if', Jourdtiin, Ann. des Sci. Nat. IS>!). slriee 4, 701. sii. Also q imted by Parker, of wiiuse p:ilxrs IIovlisteltrr docs not, :qqiew to hare been cogiiizimt. Tliis is t,o be rc+grrt,tcd, as tile twu tliffw o n 1 oilits oT cousidnrable interest.

1‘1G M R . A. S. WOODWARD ON [Feb. 21,

tainly not lessened by current advance, for Boas has lately shown most conclusively’ that the pulmonary artery is homologous through- out the vertebrate series.

2. Palzontological Cont r ibu t ions to Selachian Morphology. By A. SMITH WOODWARD, F.G.S., F.Z.S., of the Br i t i sh Museum ( N a t u r a l His tory) .

[Received January 17, 1888.1

I. On the Laterul Lirie of a Cretaceous Species of Scylliide. I t has long been known that the canal investiug the sense-organs

of the “lateral line” in Selachian fishes attains, as a rule, to a considerahlg Iiigher stage of developnieut than in the Chinim-oids. While in the latter tlie c a r d is merely an alien groove, supported by a series of iucoriiplete ring-like dermal calcificat,ions, in the fornier it assunies a tubular clr;iracter, opening externally by a row of smnll orifices, either iu its own root; or through short secondarily developccl diverticula.

Only two undoubted exceptions to tliis ride appear to have hitherto Iieen placed on recoitl. The living Echino~hinus is showii by Solver’ to have the lateral line iu t he form of an open groove, ttiouzh this apparently is not supported by any ruiniite calcifications ; and very similar is the lateral liue of Ci~lamydoselachus, as described by Gar- man3. The supposed Liassic Selachian, Squaloruja, may also be assumed to have exhibited a similar condition of this organ, the small Iialf-rings origiiially supportiug it beiiig very clearly seen in several fossils recently descrilied brfore this Society *, and axreeing in every respect with those met with in Ischyoduu and Chimera. Both of the first-named genera, however, are of a comparatively primitive cha- racter, arid Squulorajo shows several other inarks of resemblance to the Chinireroids, so that the fact is not unexpected. But I have lately observed suggcsstive traces of a similarly embryonic lateral line in a most sprcializd modern type of Selachian ; aid as this appears to be a11 udooked-for novelty, it may be deemtd worthy of a brief iiote.

The Shark in question is a small fossil species, discovered in the Upper Cretaceous strata of -Mouiit Lebauoo, Syria, arid provisioiially assigned by Pictet and Humbert ’ to the genus Xcyllium, under the

“ Ueb. (1. ilrterion bogoii der Wirbelthiere,” Morpliolg. Jahrb. vol. xiii. 1587, p~11.3. See also ilrid. vol. vii. 1’. 488, and 701. viii. 13. 169.

U. Solgor, ‘ N e w Uiiter~ttcliungen ziir dnatornie dcr Seiteriorgsne der Fiwclie,’ drohiv m i h . hit i t . vol. sv i i . (1880), p. 9ti.

S. G-;~riiian, * ‘ ClLlrc.m!/doselnchi~s uncpiisess, Garm., a living species of Clado- clont Shark,” Bull. Mus. Gonip. Xool. a a r v a r d Coll. vol. xii. 110. I (1583), p. 3.

Smith Woodward, ‘ Nuto 011 the Lateral Line of Sqikdurc$a,’ P. Z. S. 1887, p. 481.

F. J. Pictet t?t A. Humbert, ‘Nouv. Rech. Poise. POPS. Mont Liban,’ p. 11 1, pl. xviii. figs. 2-4.