540 



MR. D. W. DEVANESEN ON THE 



incipient stage in ossification by substitution (text-fig. 9 B). No 

 cartilage cell could be seen. The Haversian system may not be 

 expected, as the pubis, if at all ossified, is more likely to become 

 a spongy or cancellated bone. A median translucent mass (A.) 

 found at the symphysis, I presume is a residue of the decaying 

 cartilage not yet replaced. In this connection, I may mention 

 that a similar phenomenon has been noticed in another toad, 

 namely Pelohates (Gadow, p. 27). 



Among the bones of the hind-limb, the femur, the " os navi- 

 culare," and the prehaJlux deserve attention. There is, on the 

 ventral side of the femur, a distinct crest stretching from the 

 middle to the anterior end, stopping short of the head of the 

 same. It is from this " femoral crest " that the vastus internus 



Text-figure 10. 



A dorsal view of the ilio-sacral joint and a few muscles connected witli the same. 

 For lettering consult the key-list of abbreviations. 



muscle arises. To this crest is also attached a considerable 

 number of fibres of the adductor longus, adductor brevis, and the 

 2)ectmeus (text-fig. 19 B and C). 



The OS naviculare in the tarsus of this toad is a circular disc, 

 convex in front and concave behind, and articulating exclusively 

 with the astragalus. In front it is bound by tissue, and articu- 

 lates as well with a certain piece of highly calcified cartilage 

 which, as will be seen presently, is homologous with the prehallux 

 of JRana. Though the tarsal bone in question has become so 

 closely associated with the prehallux as to look like one of the 

 component pieces of the latter, yet its identity could be recog- 



