ART. IS ANATOMY OF CHINESE FINLESS PORPOISE HOWELX. 29 



cranio-ventral margins of the transverse processes and bodies of 

 several of the more cranial thoracic vertebrae, and is inserted first 

 upon the expanded ventral portion of the atlas and upon the basioc- 

 cipital much after the fashion illustrated by Schulte for Balaenof- 

 tera. In fact, this muscle mass as a whole appears to be very similar 

 to that of the latter genus : but Kogia has no longus capitis — only a 

 rectus capitis anterior minor and longus colli. Phocaena has all 

 three, as has Glohioceyhala. 



MUSCLES OF THE THOKAX 



As the sternum of Neomeris is so greatly reduced, the pectoralis 

 is small, and although it may well be divisible, this could not be 

 demonstrated because of the condition of the specimens. There is 

 no scapular attachment. Origin is less than 50 mm. broad, from the 

 lateral fossa of the cranial half of the sternum, with insertion upon 

 the disto-caudal portion of the medial aspect of the humerus. 



In Kogia the pectoral is double, with a third slip corresponding 

 to the abdominal pectoral. In this genus the deeper pectoral inserts 

 upon the coracoid, and this is the case in Phocaena as well. In 

 Balaeno'ptera the muscle is single, as is apparently also the case in 

 Phocaena. In Glohiocephala there are two divisions, but the ectal 

 one is shown as many times the size of the ental. In all of these the 

 pectoral mass is very much more extensive than in NeotJieris^ which 

 is correlated in large part with the fact that the sternum is much the 

 most restricted in the latter. 



The sei'ratus magnus or anticus arises by muscle bundles from 

 about the third to the sixth or seventh ribs ; but the muscles of this 

 region were in bad condition and the extent of the attachments could 

 be distinguished only approximately. The muscle passes over the 

 more caudal portion of the medial face of the scapula and is inserted 

 upon the scapular membrane for a short distance in either direction 

 from the glenovertebral angle. It is weak in its development. 



As might be expected, origin of this muscle is variable among the 

 Cetacea. In Balaenoptem Schulte states that origin is from the 

 fourth, fifth, and sixth ribs, while for the same genus Carte and 

 McAlister found it coming from the eight most caudal ribs, with a 

 slip from the second. In Kogia., however, origin is from the first 

 three ribs, while in Phocaena it extends to the fifth. Murie states 

 that in Glohiocephala this muscle extends from the transverse proc- 

 ess of the atlas to well toward the caudal part of the thorax, but 

 this seems questionable. Insertion is very similar in all. 



No attempt w^as "made to investigate the intercostal or sternocostal 

 muscles. 



