38 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 70 



manner indicated in Figure 13. In the other cetaceans it seems to 

 be very similar. 



The humeral head of the triceps is represented by a remnant of 

 tendon which extends from the cranial portion of the medial tuber- 

 osity of the humerus just distad of the attachment of the masto- 

 humeralis, to the olecranol process of the ulna. 



There is no muscle attached to either the acromion or the coracoid 

 process, and the remnant of a triceps is the only muscle extending 

 distad of the humerus. The limb of Neomeris is, therefore, unique 

 among the cetaceans so far dissected in having the musculature of 

 this member so simple, in this respect indicating a very specialized 

 condition. The radius and ulna are invested in a thin layer of 

 fibro-cartilage that is extremely tough. In spite of careful search, 

 nothing that could be interpreted as the vestige of any other muscle 

 of the flipper was encountered. 



After removal of the integument from the fore limb it is seen 

 that the fibro-cartilage is arranged in a definite manner, as suggested 

 in Figure 12. The fibers converge distad from the base of each digit 

 and the digit on either side adjoining, this suggesting the appear- 

 ance of the plates of cancelloid tissue within the extremities of the 

 larger limb bones of most mammals. Just as the latter are arranged 

 to withstand stresses from the directions in which these are usually 

 applied, so it may be presumed that the fibrous tissue of the cetacean 

 flipper has a definite plan for strengthening this member. 



PELVIC MUSCULATURE 



There is apparently no levator ani in Neomeris such as is shown by 

 Schulte for Kogia^ but placed almost similarly is a levator vulvae, 

 originating from the membranous sheath of the pelvic bone and 

 inserting into the tissue about the vulva. It lies superficial to a part 

 of the ischiocaudalis. This also originates from the pelvic sheath, 

 with fibers running caudo-ventrad to the midventral line. It is shown 

 for Kogia and corresponds at least in position and direction with the 

 coccygeus of Balaenoptera. 



There is a muscle corresponding in position to the ischiocavernosus 

 as given for Kogia. It arises from the pelvic sheath, its fibers inter- 

 digitating with those of the rectus abdominis. I doubt if the true 

 ischiocavernosus is as distinct in the female as is this muscle, but 

 it is so termed provisionally. 



The deeper parts of the muscles of the anal region were much 

 hardened for some reason, and they were mutilated by the median 

 incision made before the specimens were immersed in the preserva- 

 tive. For these reasons my dissection here was unsatisfactory and 

 no attempt was made to homologize these muscles. 



