ABT. 13 ANATOMY OF CHINESE FINLESS PORPOISE HOWELL 23 



The tnasseter occurs in two divisions. The pars sui^erficialis has 

 origin from the tissue about the termination of the zygomatic process 

 of the squamosal and the postorbital process of the frontal, and is 

 inserted upon the membranous covering of the ventro-lateral border 

 of the mandible. In the first specimen dissected this division was 

 relatively robust, but in the second its development was extremely 

 slight. Due to the weak origin of this part it can have but slight 

 functional importance. The pars profundus is also small and has 

 origin, not from any bone but from the tough tissue within the orbit 

 and beneath the styliforpi process. Insertion is upon the dorsal mar- 

 gin of the mandible adjoining. This division is stronger than the 

 superficial, but yet one is forced to the conclusion that neither plays 

 an important part in the economy of the animal. 



The masseter of NeomeHs is much smaller than in Kogia and is 

 not involved with the tough, fibrous, superficial musculature of the 

 cheek. The origin is farther caudad than in the latter genus, which 

 changes the inclination of the fibers. That of Balaenoptera seems 

 also to be comparatively somewhat larger, while it is difficult to 

 judge of the development in the figure of Glohiocephala. 



The temporalis is small and evidently indivisible. It arises from 

 the temporal fossa and passes beneath the postorbital process of the 

 frontal. Insertion is upon the border and adjoining lateral face of 

 the coronoid process of the mandible. 



Comparison of the skull of Neomeris with those of Kogia,, GloHo- 

 cephala,, and Tursiop^ indicates that although the temporal is rela- 

 tively no broader in the three last-mentioned genera, it is much 

 deeper and more robust. Comparison of the skull of Neomeris with 

 that of Balaenoptera is hardly practicable, due to the difference in 

 size; but Schulte's figure indicates that the temporal is broader in 

 the last-mentioned genus. The temporal of Neomeris,, in fact, must 

 be regarded as slightly developed and correspondingly weak. 



No separation of the pterygoideus was possible in the present 

 animal. Origin is from the membrane investing the falcate process 

 and the portion of the border of the pterygoid bone adjoining, as 

 far rostrad as the notch for the passage of the internal auditory tube. 

 Insertion is not upon the mandible, but upon the tough tissue near 

 the ear bone. Hence, this muscle is nonfunctional as far as its usual 

 duties are concerned, but it may have some use in connection with 

 the neighboring trabeculated air sinus. 



In Kogia the pterygoid is not only described as double, but the 

 internal division is again separable. Insertions of all are upon the 

 mandible, and they seem to be well developed. Schulte found the 

 muscle to be double in Balaenoptera also, but Carte and McAlister 

 reported it as single in the same genus. The former authority 



