1908.] ON THE ANATOMY OF A FROG. 11 



3. On the MiTSCiilature and other Points in the Anatomy of 

 the Engystomatid Frog, Breviceps verrucosus. By 

 Frank E. Beddard, M.A., F.B.S. 



[Received December 11, 1907.] 



(Text-figures 2-13.) 



I have examined or dissected three examples of a species of 

 Breviceps, which I refer to the species " verriicosics" on the 

 following grounds. In the definition of the Frog by Boulenger * 

 the body is stated to be " entirely covered with distinctly porous 

 granular glands." This was the case with my specimens, which 

 therefore appear to differ from Breviceps gibhosus. Inasmuch as 

 our knowledge of this Afi'ican and ant-eating Batrachian seems 

 to be confined to its external and osteological characters, I have 

 thought it worth while to biing before the Society a further 

 contribution to the knowledge of its structure. The notes upon 

 which the present communication is founded chiefly relate to 

 those structures which are known to vary in their characters 

 among the Anurous Amphibia. Other characters, however, are 

 not altogether ignored. 



§ Pelvis and Coccyx. 



It is of course well known t that BrevicejJs is distinguished from 

 {e. g.) Rana by the widely expanded transverse processes of the 

 sacral vertebra and by the fusion of that vei'tebra with the 

 ensuing coccyx. Since the latter point at any rate has been 

 found, though rarely, to vary among the Anura, it is perhaps 

 woi'th while to record here the fact that I found in two specimens 

 a complete fusion between the sacrum and the coccyx. When 

 the frog is extended with the dorsal surface uppermost, the ilia 

 are not visible as they are in Rana to a great extent, and the 

 ilio-coccygeal muscles descend on a plane which only forms a 

 small angle with the plane of a sagittal section. The sti'ongly 

 expanded transverse processes of the sacral vertebra show no 

 connection with the ilia when viewed from above. These bones 

 are quite invisible if the dorsal surface of the transverse process 

 has been cleaned and the underlying musculature left alone. 

 The attachment of the ilia, in fact, is not to the edge of the 

 broad transverse process as in some other Batrachians^ but is 

 completely ventral leaving the edge entii-ely free. 



Another structure in connection with the pelvis of Breviceps 

 remains to be described, which I have not noticed, or seen a 

 description of, in other Fi-ogs. On the dorsal surface of each 

 -sacral transverse process, lying, apparently, freely on that process, 

 is a flat and somewhat oval plate of cartilage not so long as the 

 transverse process is in an antero-posterior direction. This plate 



* Cat. Batr. Sal. 1882, pp. 176, 177. 



t " Amphibia" in Bronn's Thiefreich, pp. 608 & 640. 



