1914.] NATURAL SCIENCES OF PHILADELPHIA. 439 



In both the Massachusetts and New Jersey skulls the large foramina 

 in the maxillae are almost opposite those in the premaxillae, while 

 in the Osteographie figure the former are considerably in advance 

 of the latter. 



The peculiar characters of the skull which distinguish M. densi- 

 rostris are the deep rostrum and the depth and shape of the rostral 

 portion of the premaxillae; the large, forwardly directed foramina 

 in the maxillae which connect with the grooves on either side of the 

 rostrum; the appearance of the malar in the bottoms of the anteor- 

 bital notches; the large palatines which entirely surround the 

 pterygoids; the trifoliate foramen magnum and the mandible, each 

 ramus of which is greatly swollen in the region of the single triangular 

 tooth. 



The skeleton has the following vertebral formula: 



C D L Ca 



7 10 11 16 = 44 



Certainly one, and possibly two, of the terminal caudal vertebrae are 

 missing, so that the correct formula should probably be: 



C D L Ca 



7 10 11 18 = 46 



A skeleton of this species from the island of Lord Howe, Australia, 

 has the following formula, according to Van Beneden and Gervais: 



C D L Ca 



7 10 11 17 = 45 



This whale measured 15 feet 9 inches in length, while the New Jersey 

 specimen was 14 feet 5 inches long. 



Allen gives the number of vertebrae in the Massachusetts skeleton 

 as 45, but says it has only nine pairs of ribs, while both others have 

 ten pairs. It is probable that the terminal pair in Allen's specimen 

 may have been lost, as Cetacean skeletons are so frequently deficient 

 in this respect. 



The first three cervical vertebrae of the New Jersey whale are 

 solidly ankylosed, but the remaining four are free. 



The dorsal and lumbar vertebrae have the thigh, thin spines and 

 short transverse processes so characteristic of the Ziphioid whales. 



Nine chevrons are present, but the first and penultimate members 

 of the series seem to be lacking, and I believe that eleven is the normal 

 number. 



There are ten pairs of ribs, the first seven on each side articulating 



