THE CHEIEOPTEBA. 455 



circle. As a consequence, the axis of the sacrum is at 

 risht ancles to that of the anterior thoracic vertebrse. 



In the skull, the orbit is not divided by bone from the 

 temporal fossa, and the premaxillse are relatively small, and 

 sometimes altogether rudimentary. 



The clavicles are remarkably long and strong, and the 

 broad scapula has a strong spine. The ulnae are imper- 

 fect distally, the carpus being borne altogether by the 

 radius. There is only a single bone in the proximal row 

 of the carpus, the pisiform being absent. Those digits of 

 the maniis which are devoid of nails, possess not more 

 than two phalanges. 



The pelvis is very narrow and elongated, and the pubic 

 bones are widely separated at the symphysis, as in some 

 Insectivora. The anterior caudal vertebrae and the ischia 

 are frequently iinited. The axes of the acetabula are 

 dii-ected towards the dorsal side of the body as well as 

 outwards ; whence, in part, arises the peculiar position of 

 the thigh, which has already been described. The fibula is 

 rudimentaiy, its upper part being represented only by 

 ligament, and there is an elongated bone, or cartilage, 

 attached to the inner side of the ankle-joint which lies 

 in and suppoi-ts the patagium, and is called the calcar. 

 The distal moiety of the tarsus readily rotates u]Don the 

 astragalus and calcaneum, permitting the sole to turn 

 inward with much ease. 



All Cheiroptera possess three kinds of teeth, incisors, 

 canines, and molars ; and the intestine is devoid of a coecum. 



The heai-t is provided with two superior cavae, a right and 

 left ; and the smooth cerebral hemispheres leave the cere- 

 bellum completely exposed. 



The testes are abdominal throughout life, or may 

 descend into the perinaeum, but there is no true scrotum. 

 The penis is pendent. There are vesiculas seminales. The 

 form of the uterus varies, being sometimes rounded and 

 sometimes two-horned. 



The Bats are ordinarily divided into the Fnigivora and 

 the Insectivora. 



I 



