PIIOC.ENA COMMUNIS. 121 



also vary j^reatly iu proportious, Me sliall gain notliiug by couii)iuisou. 

 (>!i this point we must await tbe result of future luvestigations 



\Vc tuiii finally to the question of color. The color of F. Ilncafa is 

 accurately described by Professor Cope (1. c.)- The back ui)per half of 

 the head, posterior part of the tail, flukes, and pectoral fins are black. 

 The sides are pinkish aud the belly is white. A black line passes from 

 the base of the pectoral fin to the corner of the mouth. The edges of 

 the lower lip are black. The Cape May female and another female 

 si>ecimen, 5 feet 1 inch loug, have nearly the same coloration, except 

 that the sides are yellowish instead of pink and the light color of the 

 belly extend!^ nearly to the flukes aud leaves only a slight band of dark 

 color around the lower lip. The Cape May specimen also has no dark 

 band from the pectoral fin to the mouth, but it exists iu the second 

 female. Are these differences in color sufficient to warrant the repara- 

 tion of P. lineaiaf 



M Fischer's figure of au old female (PI. vii, fig. 1) agrees in colora- 

 tioii and form with the cast of P. Uncata, except that the sides are gray 

 instead of pink and that the baud of color from the pectoral fin to the 

 mouth is broad and gray instead of narrow and black. 



In point of color, Scammon's description of P. vomerina is applicable 

 to M. Fischer's specimens of P. communis. I subjoin Scammon's descrii)- 

 tion of the female of P. vomerina and the description by Lafont of a 

 female of P. communis: 



r. communis (female). 



Dos noir j flaucs d'uu gri.s do ter juspd 

 de Llanc; abdomen d'uu blanc mi pen 

 gii.sa.tre; pectorals iioires; uneligue noire, 

 tres etroite, part de leur attaclae et .so 

 dirige vers la commissure labiate ; rostro 

 noir. (Lafout.) [Fischer, 1. c, p. IG.'j.] 



r. vomerina (female). 



The female is of the same color above 

 (black) ; it is lighter ou the sides, with a 

 narrow blacti streak running from the 

 coiniu- of the mouth to the pectorals, and 

 the lower i)ortiou of the animal is of a 

 milky whiteness; yet the pectoral and 

 caudal tins are black underneath or of a 

 dark gray. [Scammon, Marine Mam., 

 p. 95.] 



It will be observed that Lafont's specimen only differs in having the 

 white of the belly ''un pen grisatre." In another specimen this region 

 was white, as in Scammon's P. vomerina. 



Summing up the available evidence I find no reason to regard P. 

 hrac'lujcion or P. vomerina as distinct from P. communis. P. Uneata, if 

 distinct, difiers only iu color, a character which in this genus must be 

 looked upon with distrust. 



