322 REPORT OF NATIONAL MUSEUM, 1884. 



investigation draw our opinions regarding the variations of other spe- 

 cies. In the present instance it is hoped that a considerable number of 

 crania may be secured at no distant day. 



What has been said concerning species described from single skulls 

 holds true for species described from external characters only, and of 

 which no measurements are recorded or specimens preserved. It is 

 doubtful whether such species should be recognized. 



At least three species have been described which, so far as external 

 appearance is concerned, bear a more or less close resemblance to the 

 specimen under consideration. 



First may be mentioned the Belphinus maculatus of Lesson and Garnot, 

 (Zool. Voyage Coquille,p. 183), seen in the vicinity of the Society Islands. 

 This quondam species has the sides and belly impure grey, with rounded 

 white spots margined with rose-color. As this is one of the species vus 

 en mers et destines a distance, it is scarcely worthy of serious considera- 

 tion, but it is evident that even so far as the spots are concerned — the 

 only definite character given — it bears no close resemblance to the Pen- 

 sacola dolphin, and it may therefore be dismissed. 



Another spotted species is the Belphinus Boryi of Desmarest (Mam- 

 malogie, p. 513), from Madagascar. Its colors are thus described: 

 " Dessus du corps d'un gris de souris fort tendre ; dessous d'un gris 

 tres clair, avec des taches, peu tranchees, d'un gris-bleuatre j cdt6s de 

 la tete d'un blanc d'ivoire, nettement s6par6 par uue ligne droite, de la 

 couleur du dessus." The color of the head and of the spots is evidently 

 quite different from that of the specimen under consideration. 



A third species, with a spotted skin, is the Belphinus Pernetyi of Des- 

 marest (Mam., p. 513). Pernety's figure, though somewhat crude, evi- 

 dently represents a species whose coloration is similar to that of our 

 Pensacola dolphin. The transition from light to dark color is represented 

 as very abrupt, the light color involves the eye and the beak, and the 

 back is without spots, in all of which characters Pernety's dolphin differs 

 from that represented in the plates accompanying this essay. The last 

 character, however, seems to be of little significance. I was informed 

 by one of the naturalists of the Albatross that in the schools seen off 

 Hatteras the young animals were not spotted on the back. 



If our Pensacola specimen is to be accredited to any species known 

 only by the exterior, I believe it should be to this B. Pernetyi. As no 

 portions of the animal were preserved, however, and no diagnosis or 

 measurements were given, I think it undesirable to withdraw the 

 species in question from the list of especes douteuses. 



There is at least one other species which seems to bear some relation 

 to that under consideration. This is the Belphinus punctatus of Gray. 

 A skeleton, drawing and measurements of this animal are preserved in 

 the Public Museum of Liverpool, where I examined them in the winter 

 of 1883-'84. Gray's figure (Cat. Seals and Whales, p. 399) is a correct 



