1894.] ON THE TADPOLE OF SENOPUS EJEVIS. 101 



EXPLANATION OF PLATE XII. 



Reference letters : — a.h., haemal arch ; a.n., neural arch ; c, vertebral body ; sy,, 

 synostosis. The small numerals indicate the vertebrae (or, where two occur, the 

 intervertebrae) which form the vertices of the curves. 



Fig. 1 a. Sole. Vertebral column with five sinuations. From the left side, f 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. B. C. S. 364. f- nat. size. 

 3 a. Perch. Line of curvature of the backbone (with three sinuations), with 



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



3 b. The same. Curvature, enlarged for comparison with lb and 2. § nat. 



size. 



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



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

 4 b. The same specimen. First five vertebras. X 2. 



5. Sole. Portion of a vertebral column with vertebrae nos. 14 to IS com- 



pressed and co-ossified, f nat. size. 



6. Sole. Portion of a vertebral column, with vertebrae nos. 23 to 34 com- 



pressed. B. C. S. 500. § nat. size. 



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

 of the Teratological Series in the Museum of the Eoyal 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 lavis {Dactylethra 

 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 sublimate 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 1 , a description which was subsequently 2 

 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 (Silurana) of Frogs from West Africa," Ann. 

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



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



