346 THE ANATOMY OF VERTEBRATED ANIMALS. 



ceps extensor is represented by tendinous fibres in wliicli muscle 

 cannot alvvaj^s be detected, which extend from the posterior face 

 of the humerus to the ulna. The other muscles of the forearm 

 and all those of the manus are absent. The dorsal muscles 

 form a thick continuous mass from the end of the tail to the 

 occiput ; and, on the ventral side of the spinal column, the 

 subcaudal muscles are similarly continued forward, as far as 

 the middle of the thorax. An ischio-caudalis passes, on each 

 side, from the anterior chevron-bones to the ischium. Between 

 their attachments is an ^..poneurosis which supports the anus ; 

 ischio-cav^ernous muscles pass from the iscliia to the corpora 

 cavernosa. 



The diaphragm has no tendinous centre. Its pillars are 

 very thin, and, extending between the kidneys and the spine, 

 become tendinous, and are attached to the ventral faces of the 

 vertebrae, as far as the ninth lumbar. A strong fibrous apo- 

 neurosis is continued back over the subvertebral muscles to the 

 pelvic bones. Between these bones and the ends of the trans- 

 verse processes of the twenty-eighth and twenty-ninth verte- 

 bras (counting from the first dorsal) the aponeurosis is so stout 

 as to form an almost distinct fibrous band, which occupies the 

 j3lace of an ilium. The ureter lies between the ischio-vertebral 

 fascia and the peritonaeum. 



The teeth are small and numerous, and their crowns are 

 obtuse and constricted. The passage of the pharynx is di- 

 vided in the middle, the soft palate being prolonged into a mus- 

 cular funnel, the opening of which closely fits the constricted 

 neck of the long cone into which the epiglottis and the aryte- 

 noid cartilages are produced. Thus the arrangement which is 

 transitory in the Marsupial is permanent in the Cetacean. 



The stomach is divided into three sacs. The first is large, 

 conical, and lined by a coarse white epithelial coat. The gul- 

 let opens directly into it. The second stomach communicates 

 with the first by an aperture which is close to the cardiac end 

 of the gullet, and is surrounded by a very prominent rugose 

 lip. A curved passage about one inch long and caj^able of 

 admitting the finger, lined by a white epithelium similar to 

 that of the first, leads into the second stomach. The second 

 stomach is lined by an extremely vascular and soft mucous 

 membrane, with about ten strong longitudinal folds, separated 

 by deep sulci, interrupted by transverse ridges. A narrow 

 and curved canal leads from this into the third stomach, which 

 has a tubular form and is bent upon itself. Its lining mem- 

 brane is quite smooth. A small, circular, pyloric aperture 



