22 



BULLETIN 36, UNITED STATES NATIONAL MUSEUM. 



So far as external appearances are coucernetl there are apparently 

 few points of resemblance between the two species. Tbe depression 

 and great extent of tbe dorsal fin, so strongly insisted upon by Pncberan 

 as a character of ;S^. 2>Jumbca, is not shared by aS'. Icntiginosa, and the 

 measurements do not agree. The color of the body of 8. i)lum})ea is 

 described by F. Cuvier as being of "one teinte nniforme d'au gris 

 plombe, excepte Pextremite et le dessous de la machoire iuferieure, 

 qui sout blanchatres."* The color of S. Icntiginosa, according to Pro- 

 fessor Owen, is "pretty uniformly bluish cinereous, or slaty, freckled 

 with irregular small spots or streaks of brown or plumbeous pigment, 

 the streaks longitudinal and flecked with white ; the under surface is a 

 shade lighter thau the rest of thebody."t 



I think we may look upon the two species as distinct, and do not 

 fear that future evidence will invalidate this conclusion. 



Table of measurements of the lype-skitll of Sotalia plumbea. 



*Mammif6res do la Menagerie dn Museum, C0° livrasion. 

 tTrana. Zool. Soc, London, vi, 18CG, p. 20. 

 } Collected by Dussumier, 1837. 



(Fide Puoberan.) 



