1893.] 



NATURAL SCIENCES OF PHILADELPHIA. 



231 



Brain of Cryptobranchus maxim us. 

 C H, cerebral hemispheres ; op, optic 

 lobes; Cr, cerebellum; M, medulla ; S, 



spinal cord ; I, II, 

 cranial nerves. 



IJI. IV, V, VII, 



Except in the points of disa- 

 greement just mentioned, condi- 

 tioned through the absence of 

 the gill opening, it will be ob- 

 served that the hyoid apparatus 

 of the Japanese batrachian 

 agrees essentially with that of 

 the American one. The general 

 character of the brain and the 

 manner in which the cranial 

 nerves arise and are distributed, 

 are essentially the same in both 

 batrachians. 



As might be expected on ac- 

 count of the similarity in the 

 skeleton of the two animals the 

 disposition of the muscles is essen- 

 tially the same. Indeed, as re- 

 gards the cranial muscles, the 

 only noticeable difference is the 

 absence in the Japanese batrach- 

 ian of the constrictoresandadduc- 

 tores arcuum and the modifica- 



tion of the ievatores arcuum conditioned by the absence of the gill 

 opening. The remaining important muscles of the skull and hyoid 

 apparatus, such as the temporal, masseter, digastric, sub-mentalis, 

 sterno-hyoid, genio-hyoid and cerato-hyoid, are distributed in much 

 the same manner in both animals. 



The alimentary canal with its appendages, does not differ in the 

 Japanese batrachian in any respect from that of the American form 

 except that in the former animal, just within the lower jaw, two 

 larger racemose glands, about two inches long, were found, the 

 ducts of which opened on the floor of the mouth. From their 

 position and structure it is to be inferred that these glands 

 are salivary in function. Up to the present time, however, neither 

 submaxillary nor any other kind of distinct salivary glands have 

 been observed in the amphibia. The only notable difference in the 

 disposition of the vascular system in the Japanese animal as compared 

 with the American is that in the former there are three branchial 

 vessels, 1, 2, 3, Plate V, fig. 1, while in the latter there are four. 



