1894.] O-S THE TADPOLE OF XENOPtJS L^EVIS. 101 



EXPLANATION OP PLATE XII. 



Eeference letters : — a.h., hsemal arch ; a.n., neural arch ; c, vertebral body ; sy., 

 synostosis. The small numerab indicate the Tertebrse (or, where two occur, the 

 intervertebrse) which form the Terticea of the curves. 



Fig. 1 a. Sole. Vertebral column with five sinuations. From the left side. | nat. 



size. 

 1 b. The same. Lines of curvature. - 

 2. Sole. Line of curvature of a backbone with three sinuations, and a 



feeble fourth one posteriorly. 7?. C. S. 364. f nat. size. 

 3 a. Perch. Line of curvatvire oi' the backbone (with three sinuations), vrith 



contour of the animal's body in relation to it. B. C. S. 364. ^ nat. size. 



3 h. The saiiw. Curvature, enlarged for comparison with 1/) and 2. f nat. 



size. 



4 a. Sole. Portion of a backbone with curvature involving vertebrse nos. 30 



to 35, with marked angulation of those posterior to them, f nat. size. 

 4 h. The same specimen. First five vertebrae. X 2. 



5. Sole. Portion of a vertebral column with vertebra; nos. 14 to 18 com- 



pressed and co-ossified. | nat. size. 



6. Sole. Portion of a vertebriil column, with vertebras nos. 23 to 34 com- 



pressed. B. C. S. 500. I nat. size. 



B. C. S. and the accompanying numbers refer to the ' Descriptive Catalogue 

 of the Teratological Series in the Museum of tlie Koyal College of Surgeons of 

 England,' ed. 1893 ; and the specimens depicted in figs. 4 & 5 have been pre- 

 sented to that Institution by Prof. Sutton, but not yet catalogued. 



2. Notes upon the Tadpole of Xenopus Icevis [Dadylethra 

 capensis). By Frank E. Beddard_, M.A., F.R.S., 

 Prosector to the Society. 



[Eeceived February 6, 1894.] 

 (Plate XIII.) 



During the past summer one of the specimens of Xenopus Icevis 

 at the Society's Gardens deposited a quantity of ova, which duly 

 hatched out. Ultimately a few frogs were bred from the tadpoles. 

 I preserved a series of tadpoles from the newly-hatched larva 

 onwards, partly in corrosive subhmate and partly with Perenyi's 

 fluid ; the following notes refer to my examination of those 

 specimens. But, before proceeding to describe the external and a 

 few of the internal characters of the tadpoles, I will briefly direct 

 attention to previous work upon the subject. 



The earliest description of the larva known to me is by the 

 late Dr. J. E. Gray', a description which was subsequently^ 

 expanded and illustrated. The figure of the tadpole, showing 

 the tentacles, does not show the dorsal fin, and is in other respects 

 not good. In the definition of the tadpole (described as a distinct 

 genus Silurana) we find the remark : " belly and underside of the 



1 " Notice of a new Genus {Silv/rana) of Frogs from West Africa," Ann. 

 Mag. N. H. (3) xiv. p. 315. 

 8 " Note on the Clawed Toads {Dactylethra) of Africa," P. Z. S. 1864, p. 458. 



