loO BULLETIN 36, UNITED STATES NATIONAL MUSEUM. 



No. 21048 of tlie American series (p. 132) we find a skull which lias 

 the beak relatively as narrow and the intermaxilhe both relatively and 

 absolutely narrower. The teeth are of the same number (4-4), and as 

 large as in the American series. 



Apparently no characters of genuine importance have been brought 

 forward to prove the distinctness of the grampus of the Cape of Good 

 Hope, and until such are forthcoming it seems reasonable to regard it 

 as identical with the G. grisens of northern waters. 



Grampus Stearnsii Dall. 



A mandible and two teeth are the only specimens of the west-coast 

 grampus in the national collection. The mandible is apparently neither 

 the ISTo. 1 nor the No. 2 of Mr. Ball's description ;* at least I can not 

 make my measurements agree with his. The mandible is from the same 

 locality, however, as that from which Mr. Ball's sjiecimens were ob- 

 tained, and the teeth are of the same number (3-3) as in his No. 1. It 

 may be that I do not interpret his measurements correctly, and that 

 this is his No. 1, The proportions of the jaw are as follows: 



Measurements. 



13021. Monterey, Cal. 

 (C. M. Scammon.) 



Inches. 



Centi- 

 meters. 



Totallengtli 



Length of tbe sj'mpliysis 



Greatest depth at the symphysis 



Distance from the anterior extremityof the jawto the end of the tooth line. 

 Vertical depth at the corouoid process 



17.6 

 1.95 

 1.7 

 2.6 

 4.75 



44.7 

 4.9 

 4.3 

 6.5 



12.0 



Upon examination, it appears that the coronoid process of this jaw 

 is a little higher than is common in G. grisens, and the posterior portion 

 of the ramus is somewhat less convex, but I make this statement with 

 all reserve, however, since 1 have examined only about ten jaws of G. 

 griseus, and in no two of these is the form identical. I know no reason 

 why the slight differences observable in the mandible from Monterey 

 may not be set down as indicative of individual variation merely. The 

 teeth are of the same size and form as in G. grisens. The formula for 

 the mandible under consideration is ^l', but In Mr. Ball's No. 2 there 

 were four teeth on each side — the average number in G. griseus. 



From the remarks of Scammon on p. 103 of t\i<d Jllarine Mammalia 

 it would appear that the Pacific grampus has a higher dorsal fin than 

 G. griseus ; but neither these remarks nor the figure on page 102 merit 

 the serious consideration of the classifier, since Scammon's observations 

 were made not on specimens under his hand but at liberty in the sea. 



We have, therefore, only the presumption that dolphins of the same 

 genus inhabiting different seasare likely to be specifically distinct, asthe 

 basis for the separation of G. Stearnsii from G. griseus. 



*Scamraou. Marine Mamraalia, p. 300. 



