44 



BULLETIN 36, UNITED STATES NATIONAL MUSEUM. 



squamosal aiul tbe posterior margin of a backward extension of Ihe 

 frontal, wliile in T. iursio tbe frontal has no bacliward extension and 

 the parietal is broad inferiorly. Nnmerous other differences are pres- 

 ent, which, with those mentioned, I have not found in anj' of the varia- 

 tions of T. tursio. 



Of I he external appearance of this dolphin we know but little. Scam- 

 mon, Irom two " momentary observations," describes it "as black all 

 over, lightened a little below." His outline resembles that of a T. tiirsio, 

 except that the dorsal fin is narrower than is common in that species. 



Taile of measurements. 

 TURSIO rs GILLII. 



4. DELPniNUS Linne. 



Delpldnus, Linu<^, Systema Natursc, lOtli cd., 1758, p. 77. 

 The most salient character by which this genus, in its present re- 

 stricted limits, is distinguished is the presence of two broad and deep hit 

 eral grooves in the palate. This is, indeed, the only character by which 



