ANATOMY OF CACOPUS SYSTOMA. 



535 



relatively greater width, this being mainly fine to the spheneth- 

 moid, which is extremely short, and it does not exhibit the 

 prismatic shape usnally seen in that of Rana. Each mento- 

 meckelian of the lower jaw carries at its posterior end a carti- 

 laginous triangular piece which stretches behind and is free from 

 the other component parts of the same jaw. These two pieces 

 are useful in so far as they provide partial attachments to the 

 suh-mentalis muscle below and the genioglossios above (text- 

 fig. 4 E). 



The semilunar piece of cartilage in connection with the anterior 

 cornua of the hyoid bone in Hemisus, described and identified 



Text-fiffure 5. 



Theh5'oicl skeleton of Cacopiis systoma viewed from below. Ex.H., " extra-lij^al ' 

 A.C, anterior cornu ; P.C., posterior cornu ; B., basihyal or the h.void plate ; 

 A.C.P., anterior cartilaginous process of the basihyal ; P.C.P., posterior one of 

 the same; A.B.B., anterior bod3'-process of the basihyal or the proximal part 

 of an anterior cornu ; N., notch between the latter ; S., thick cartilaginous part 

 between the proximal ends of the two posterior cornua, probablj' belonging to 

 the latter. 



as " the extrahyal " by Beddard (1, p. 909), appears to be repre- 

 sented also in this toad (text-fig. 5, Ex.H). A closei'' approxi- 

 mation and fusion of the two extrahj^als would complete the 

 notch into a foramen corresponding to that of Hemisus. 



In the vertebral column of this toad one finds also a few 

 interesting features. The transverse processes are comparatively 

 short, taking the size of the centra and the neural arches into 

 consideration ; those of the third vertebra are the longest ; next 

 in order follow the ninth, fourth, second, eighth, seventh, sixth, 

 and the fifth; the last three may be subequal. The spinous 

 processes may be said to be absent in the first, sixth, seventh, 

 eighth, and the ninth vertebra, while in the rest it is probably 

 represented by a faint median ridge. The thick transverse 

 processes of the second, third, and the fourth vertebra, the thin 



