386 THE ANATOMY OF YEETECRATED ANIMALS. 



to the others, but, as in the rest of the vertebral column, the 

 spinous processes are very short. The ribs are long and 

 curved, so as to include a relatively capacious chest. The 

 manubrium of the sternum is very wide, and the middle of its 

 under surface raised into a crest. In the lumbar region, the 

 vertebral column is bent, so as to be concave forward and to 

 describe almost the quarter of a circle. As a consequence, the 

 axis of the sacrum is at ri^-ht ano^les to that of the anterior 

 thoracic vertebrae. 



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

 temporal fossa, and the premaxillas are relatively small, and 

 sometimes altogether rudimentary. 



The clavicles are remarkably long and strong, and the 

 broad scapula has a strong spine. The ulnse are imperfect 

 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 manus 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 In- 

 sectwora. The anterior caudal vertebrae and the ischia are 

 frequently united. The axes of the acetabula are directed 

 tow^ard the dorsal side of the body as well as outward ; 

 whence, in part, arises the peculiar position of the thigh, 

 which has already been described. The fibula is rudimentary, 

 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 supports the patagium, 

 and is called the calcar. The distal moiety of the tarsus 

 readily rotates upon the astragalus and calcaneum, permitting 

 the sole to turn inward with much ease. 



All Cheiroj^tera possess three kinds of teeth, incisors, 

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



The heart is provided with two superior cava?, a right and 

 left ; and the smooth cerebral hemispheres leave the cerebel- 

 lum completely exposed. 



The testes are abdominal throughout life, or niay descend 

 into the perinaeum, but there is no true scrotum. The penis 

 is pendent. There are vesiculas seminales. The form of the 

 litems varies, being sometimes rounded and sometimes two- 

 horned. 



The Bats are ordinarily divided into the Frugivora and 

 the Insectivora. 



a. The Frugivora live, as tbeir naip.e implies, exclusively 



