308 



THE AMERICAN NATURALIST 



fVoL. XL 



of cartilage and bone. Its structure, in general, agrees closely 

 with the corresponding region in the Japanese species, as described 

 by Osawa, except in regard to the epipubis, which is markedly 

 different. 



The pelvic girdle will first be described. Taken as a whole, 

 it has a roughly triangular form. The apex is formed by the 

 anteriorly directed epipubis, while the basal angles are formed 

 by the dorso-posteriorly directed ilia. Its ventral surface is 

 somewhat convex, and, along its posterior half, is marked by a 

 slight, median, longitudinal ridge for the attachment of muscles. 

 Its dorsal surface is concave, with the most marked concavity 

 between the bases of the two ilia (Fig. 11). The greater part of 

 the pelvis is made up of the pubis, which is divided into two parts, 

 the pubis proper, and the epipubis. 



The pubis proper is a shield-shaped plate of cartilage (Fig. 11, 

 P.), whose ventral convexity and dorsal concavity have been men- 

 tioned in speaking of the pelvis as a whole. It is almost com- 

 pletely divided into lateral halves by a median suture which is 

 especially evident at the posterior end of tlie jiclvis, between 

 the two ischia (Fig. 11, S.). On each side of this suture, slightly 

 anterior to the middle region, there is a small ojXMiing (Fig. 11, 

 O. F.), the obturator foramen. The posterior corners of the pubis 

 are elevated for the attachment of the ilia (/.), and under these 

 elevations the deep, well developed acetabula are situated. 



Anteriorly, the pubis is prolonged into a long, cartilaginous 

 epipubis (Ep.), which, instead of l)eiiig forked as in the Ja])anese 

 salamander and some other Amphibia, is a straight rod, sligiitly 

 broadened and flattened at its distal end and soniewiiat enlarged 

 both laterally and dorso-ventrally at its attaciied end. The union 

 of the pubis and epipubis is a close one, l)ut allow s considerable 

 freedom of motion. 



Firmly united with the posterior end of the pubis, an.l eontiuu- 

 ous with it, are two ohloug phites of boue, the isrhu, ils.). To- 



fhe pelvis. The ischia are separated along the uiid-He line hv the 

 median suture, hut their adjacent edges are not <,uit.> parahel, so 



There is also a small triangular piece of cartilage at their extreme 

 posterior end. 



