44 



BULLETIN 30, UNITED STATES NATIONAL MUSEUiM. 



squaiuosal and the posterior margin of a backward extension of llie 

 frontal, wliile in T. tursio the frontal Las no backward extension and 

 the parietal is broad iuferiorly. jSTumerous other differences are pres- 

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

 tions of 7'. tursio. 



or t he external appearance of this dolphin we know but little. Scam- 

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

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

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



TaMe of measurements. 

 TURSIOrS GILLII. 



4. DELPHINUS Liune. 



Delphinus, Linue, Systema Natiurp, lOtb cd., 1758, }i. 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 lat 

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



