130 The Alligator and Its Allies 



Ilio-ischio-caudalis (Plate III., Figs. I and 2, is. 

 cd., Plate IV., Figs, i and 2, is. cd.) (Ischio- 

 coccygeus). The crocodile is the nearest to the 

 typical condition in the musculature of the tail. 

 The lateral and ventral part of the tail muscula- 

 ture forms a broad mass that extends to the end 

 of the tail; it lies immediately under the skin and 

 springs from the caudal ribs (transverse processes 

 Gadow) and from the spinous processes of all the 

 caudal vertebras. The entire side musculature of 

 the tail ends cephalad in several portions ; the most 

 ventral and medial of these bound the cloaca as an 

 at least slightly developed, morphological sphinc- 

 ter; the lateral portion is attached to the pos- 

 teroventral border of the ischium; while the 

 dorsal portion is inserted by two heads on the first 

 caudal rib and on the posterior spine of the ilium. 



