70 BULLETIN 30, UNITED STATES NATIONAL MUSEUM. 



The evideuce at coiiiinaiid seems, therefore, to warraut the uuioii of 

 the three nominal species D. pseudodcJphis^ Wieg:., S. attenuata, and S. 

 capeusis iuto one. 



Prodelphinus frwnatus (F. Cav.). 



The two skulls in the Paris Museum labeled P. frccnatus, and pre- 

 sumably the types of that species, are precisely like the type-skull of 

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

 P. imnctata { = P. attenuata). It lacks the spots of the latter species, and 

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

 the belly. 



I was formerly inclined to regard Delphinns plagiodon as probably' 

 synonymous with P. doris { = P.franatus). It is somewhat different 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. froenatus. 



Supp lementary rem a rus. 



Dr. Liitkeu, in his recently-published contribution to the history of 

 Prodelpliinus and other genera, to which reference has already been 

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

 group of species.* lie presents measurements and other data regard- 

 ing four skeletons and three skulls of P. doris { = P. frccnatits), 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. II; L. lG-18; Ca. 31-33=70. P. atiemiaius, C. 7; \). 15; L. 

 21; Ca. 36-38=79-81. 



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

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

 with very numerous spots. 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 flu. There is a well-marked band between the pectoral fin and 

 the forehead. (A copy of Dr. Liitkeu's figures is given iu 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 formula? and the corre- 

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

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

 under P. froenatus. 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. 



Liitkon, K. Danske Videusk. Selsk. Skrifter, 6^. Raekke, v, 1839. 



