118 BULLETIN 3r., UNITED STATES NATIONAL MUSEUM. 



PHOCyENA COMMUNIS Lessou. 



Ddphlnus phocwna, Liun6, Syst. Nat., 10th ed., 1758, p. 77. 



rhoc,(V)ia commnins, Lesson, Mau. de Mainnialojrje, 18'27, p. 413. (Fide P^'lDwcr.) 



riiocivtia brachyciitm, Cope, Proc. Acad. Nat. Sci. Pliila., 18(55, p. ^71). 



rhocdiia vomerina, Gill, Proc. Acad. Nat. Sci. Pliila., ISCJ, p. 178. 



? Pkocwna lineala, Cope, Pmc. Acad. Nat. Sci. Pliila., 1876, p. i:?5. 



Of Pliocjeuas from the east coast of America there are in tlie national 

 colh'ction three complete skeletons, two of young individuals and one. 

 of an adult; four additional skulls ; and three casts from fresli spi^ci- 

 nieus, (J[ P. vomerina there is one young skeleton and three skulls. 

 There are also in this collection the type-cast of P. lincafa and a skele- 

 ton and two skulls of P. commimls. 



All the specimens from the east coast, except No. IGGIO, Cape May, 

 N. J., adult 9 , are from Eastport, Me., and are not adult. The numltei- 

 of vertebra^, in the three skeletons is as follows: 



(a) No. 13301, Eastport, Me., C. 7; D. 13; La. & Ca. 41=G1. 



[h] No. 13305, Eastport, Me., C. 7 ; D. 12; L. & Ca. 22 + *=1 



{€) Unnumbered, Eastport, Me., C. 7 ; D. 13; L. & Ca. 40=(i(). 



[(I) No. IGGIO, $ , Cape May, N. J., C. 7 ; D. 13 ; L. & Ca. 47=(i7. 



In the skeleton of P. vo merina the formula is as follow s : 



(e) No. 11331, California, C. 7; ]). 12; L. & Ca. 45 (4-l)t = G5 (or GC). 



Three skeletons from the European coast, mentioned by Fischei', hav c, 

 the vertebrae as follows : 



(/) C.7; D. 13-14; L. & Ca. 45-4S=G5-G9. 



It is evident that no character can be derived from difrercnces in the 

 number of vertebra'. 



In all the American skeletons the caudal artery hist jierfoiates the 

 thirty-ninth vertebra counting from the last vertebra. This is, however, 

 a character of no value in dilfereutiatiugi'. communis, since in the skele- 

 ton Ggured by Van Benedeu and Gervais (Osteog., PI. lv) the first per- 

 foration is in the thirty-eighth vertebra. 



Tu his pai)er in the Proceedings of the Philadelphia Academy, 187(J, 

 Professor Co[)e brings forward the shape of the portion of the vomer 

 visible behind the palatines as a specific character. In two of the four 

 skulls from Eastport the vomer appears behind the posterior margin 

 of the palatines, while in the remaining two it does not. The same is 

 the case as regards the four skulls from the Pacific coast: in two it 

 api)ears, in the others, not. In one of the skulls of P. communis figured 

 by Van Beneden and Gervais, the vomer is visible, in another it is not. 

 It is certain, therefore, that this character, as already' stated, is value- 

 less. 



As regards the other characters given by Professor Cope for his P. 

 brachycium, — the shape of the muzzle, the prenarial triangular area, 



* Most of the caudal vertebriT'. are laclving. 



t The last rudimentary vertebra is evidently laclciug. 



