AET. 13 ANATOMY OF CHINESE FINLESS PORPOISE HOWELL 21 



complicated than, that of Neomeris. Balaenoptera has the raphe pro- 

 longed practically to the peduncle, and its panniculus as a whole is 

 simple and much more extensive. 



FACIAL MUSCULATURE 



As the innervation of the muscles of Neomeris was not attempted, 

 due to the condition of the specimens, the homology of the facial 

 muscles is in doubt, and the names applied to them are either func- 

 tional or topographical. 



For a distance of 25 mm. from the lower lip, upon the entire side 

 of the rostrum, about the eye and in front of the ear, there is situ- 

 ated beneath the skin tough, fibrous tissue so gristly that it could only 

 be whittled away with a very sharp butcher knife, as it was impos- 

 sible to apply sufficient manual force to an ordinary scalpel for dis- 

 section of this tissue. Throughout there extend coarse, specialized 

 muscle fibers, but the whole is too nearly immobile for these to have 

 much if any muscular function. For the reasons stated, no very 

 painstaking dissection of these areas was made. The directions of 

 the fibers were, of course, carefully noted; but the interrelationship 

 of these was very complex. 



There is a fairly well defined orbicularis oculi, but the area about 

 the eye is so fibrous that the degree to which this muscle can function 

 is a question. There is also a tough layer extending from the region • 

 of the auditory tube with fibers diverging about the eye, and this 

 would probably prove to consist of several muscles. The horny 

 tissue surrounding the lips and extending caudad below the eye 

 evidently represents an orbicularis oris, but this is so hard that it is 

 difficult to understand how the animal opens and closes the mouth 

 with the facility that must be necessary. A few fibers which may 

 possibly constitute a remnant of a depressor auriculae were present, 

 but the homology of these fibers is extremely uncertain. 



There is a nasorosti^alis superficialis originating from the vicinity 

 of the medial portion of the anterior rostrum and running up over 

 the whole face. The toughness of the region, however, causes the 

 primary use of this tissue to be as a shock absorber, with the draw- 

 ing forward of the anterior lip of the blowhole as a secondary 

 function. The nasorosfralis profundus is very similar to the more 

 superficial division, but is less robust, with origin that extends 

 farther along the lateral rostrum. It is less fibrous than the super- 

 ficial part, but like it the fibers have fascial insertion craniad and 

 laterad of the blowhole. 



The original portion of the dilator naris is apparently indivisible. 

 The origin is from in front of the vertex around the margin of the 

 maxilla, from over the supraorbital prominence, and robustly from 

 the cartilagenous tissue ventrad of the lachrymal. 

 20442—27- — 4 



