70 BULLETIN 36, UNITED STATES NATIONAL MUSEUM. 



The evicUuice at coiiini iiid .seeiiis, therefore, to warrant the union of 

 the three nominal species D. i^sciidodeJphh, Wieg:., ^'. atfemiata, and IS. 

 capetisis into one. 



Prodelphhins frccnatus (F. Cnv.)- 



The two sliulls in the Paiis Museum labeled P. frcenatus, and pre- 

 sumably the types of that species, are i>recisely like the type-skull of 

 P. doris (Gray). The exterior of P. frcenatus is different from that of 

 P. punctata { = P. attcnuata). Itlncks the spots of the latter species, and 

 the pectoral fins are black, like the back, rather thau light-colored, like 

 the belly. 



I was formerly inclined to regard J>elpJtinns plagiodon as probably 

 syuouymons with P. doris { = P. frwnatns). It is somewhat diflerent in 

 color, however, and the greater size of the skulls now at command ap- 

 pears to indicate that it is a somewhat larger species than P. franiatus. 



Supplementary remarks. 



Dr. Liitken, in his recently-published contributiou to the history of 

 Prodelphinus and other genera, to which reference has already been 

 made, gives much new information in regard to this very perplexing 

 grou}) of species.* Ue presents measurements and other data regard- 

 ing four skeletons and three skulls of P. doris ( = Z'. framatus), and the 

 same regarding two skeletons which he identifies with P. attenuatus. 



These two species have the following vertebral formuhie: P. doris, C. 

 7; D. 11; L, lG-18; Ca. 31-33=70. P. aiicnuaius, 0. 7; D. 15; L. 

 21; Ca. 30-38=79-81. 



One individual of P. doris is represented iu a sketch by Captain 

 Andrea as being dark on the back, white on the belly, and covered 

 with very numerous si)ots. Another individual is represented as dark 

 greenish gray on the back, light gray on the bell^^, and with but few 

 spots or streaks, which are confined to the region in front of the pec- 

 toral fin. There is a well-marked band between the pectoral fin and 

 the forehead. (A coi)y of Dr. Liitkeu's figures is given in the plates. 

 These figures are given only to show the color-marking; the outlines 

 are diagrammatic.) P. attenuatus is represented as dark on the back 

 and ashy-gray below. 



Except as regards their different vertebral formulae and the corre- 

 lated disposition of the processes and foramina of the vertebra', the 

 specimens identified by Dr. Liitken as P. attenuatus might be placed 

 under P.frcrnatus. I am not aware, however, that any such consider- 

 able variations in the number of vertebra) as are here pointed out have 

 been recorded as occurring among individuals of a single species. 



Liitken, K. Daiiskc Videnslc. Selsk. Skrifter, &'•. Raekke, v, 1839. 



