104 BULLETIN 36, UNITED STATES NATIONAL MUSEUM. 



LAGENORHYNCHUS OBSCUKUS (Gray). 



Delpkivus ohsmrus, Gray, Spic. Zool., 1828, p. 2; Zool. Ere. & Terr., 1846, p. 37, 



pi. 16 ; Catalogue of Cetac'ea, Ist ed., 1850, p. 107. 

 Tiirsio obscurus, Gray, Catalogue, 2(1 ed., 1866, pp.264 and 400. 

 Clymenia obsciira, Gray, Proc. Zool. Soc, Londou, 1866, p. 21.5; ditto, 18G8, p. 147, 



fig. 1 (pterygoid bones) ; synopsis, 1868, p. 6, pi. 16; supplement, 1871, p. 71, fig. 



3 (pterygoid bones) ; Flower, Proc. Zool. Soc., Londou, 1883, p. 512. 

 ? Phocama australis, Peale, U. S. Explor. Exped., Ist ed., 1848, p. 33, pi. 6, iig. 2. 



Tliis species was originally described by Gray from a stuiited skin, but 

 lie afterwards included in the species a number of skulls in tbe British 

 Museum. That the latter were properly referred to the species ai)pears 

 to have been confirmed by Professor Flower upon removing the skull 

 from the tyjie-skin in J 884. (See his List, p. 28.) 



It has been customary among authors since 18G8 to refer this spe- 

 cies to Clymenia {=Prodelpliinus). In the Cr</«/o//»e, however, Gray, 

 although referring the species to Tursio, makes the remark that "the 

 skull of this species is intermediate between the Lar/enorhynchus and 

 Delphinns^^ (Catalogue Seals and Whales, p. 2G5). After going over 

 the data man^^ times it seems to me that it should i)roperly be referred 

 to the former genus. There is nothing in the characters of the skull 

 that would militate against this view, and certain considerations re- 

 garding the exterior seem to confirm it. 



First, the form of the head in the type s|>ecimen is unlike that of 

 any species of FrodcJphinus of which the exterior is known. There is 

 no real beak, but on the contrary the head slopes gradually from the 

 blowhole to the extremity, as in Lagenorhynchus acutus. 



Again, the color seems rather that of n Lagcnorhynclms than of a Fro- 

 (JeJphinus. Gray's original description contains the following data re- 

 garding the color of the body: 



Collo ventroque albidis, fascea nigra ab angulo oris nsque ad primas pectorales; 

 strigaobliqna lateral!, alba postica; ca'ternm totus uiger. 



In a young speciuien in tbe same collection tbe colors are more defined; but even 

 in the older specimens tlie lateral streaks are to be seen in certain positions — a fact 

 ■which is not shown in the drawing. (Spic. Zool., p. 2.) 



The figure of the young individual is not unlike Waterhouse's figure 

 of L. Fitzroyi (Zool. Beagle, pi. 10), wliich species, indeed, Gray made 

 synonymous with obscnra. Though somewhat generalized, the figure 

 in question, as also that of the older iudividiial on the same plate of the 

 Spicikfjia (PI. ii, fig. 3), is certaiidy unlike any FrofMpliinus we know. 



The dimensions of the adult type-skin are as follows (measured in 

 straight lines) : Total length, C5 inches ; tip of snout to corner of 

 mouth, 8.7 inches; to eye, 10 inches; to blowhole, 9.5 inches; to ante- 

 rior base of pectoral fin, 1G.5 inches ; to anterior base of dorsal fin (fol- 

 lowing the curves), 31.75 inches; length of the dorsal tin, 9 inches; 

 vertical height of dorsal fin, 7.5 inches ; length of pectoral fin, 11 inches; 

 greatest breadth of pectoral tin, 3.5 inches; breadth of caudal tins, 

 15.75 inches. 



