6. TURSTO T. PERONII. 167 



Vertebraj: C. 7; D. L4; L. I85 Ca. 34 = 73. 



Teeth, ^l. Skull small. Rostrum very loug (two thirds the total 

 length), depressed aud broad (at the middle about oue third the breadth 

 at the orbits). Triangular area iu front of nares short and only slightly 

 depressed. Temporal fossjiB very small and rounded, their length equal 

 to the distance betweeu the ante- and post-orbital processes of the 

 frontal. Zygomatic in^ocess of squamosal short. Palate with traces of 

 lateral grooves; vomer visible in the median line. 



Measurements 0/ the slciill. — {Jo. 12, Mus. Pays-Bas. Type of D. 

 louf/irosfris, Gray.) Total length, 43""; length of rostrum, 23'^'"; 

 breadth of rostrum at base, 7.5 '" ; at its middle, 4.G""; breadth between 

 orbits, 44""'; length of temporal fossa, 5''". 



Habitat. — Cape of Good llope {type); between Panama and the Gala- 

 pagos Islands {U. S. Nat. Mm.); Australia {CopenJiagoi Mm.). 



6. TURSIO Wagler. 



Rostrum long, broad, tapering and flat. Rostral portion of inter- 

 maxilla', flat. Pterygoid bones separate, the inner margins parallel. 

 Symphysis of mandible short. Teeth small, acute, aud numerous, 43 to 

 44. 



Head with a short, bat distinct narrow beak (nearly in the same 

 plane with the forehead in L.peromi). No dorsal Jin. Pectoral tins fal- 

 cate. Caudal ridges prominent. Color black above, white below, with 

 sharply defined borders. 



TURSIO PP:R0NII (Lacdpede). 

 (Plate 21, figs. 1 and 2.) 



Body thickest about opposite the pectoral fin; from thence it tapers 

 gradually to the flukes aud rather abruptly toward the end of the beak. 

 Beak short, and nearly in the same j)lane with the forehead. Lower 

 jaw slightly longer than the upper. Pectoral fins and flukes shaped 

 like those of Delphimis delphis. 



Upper part of head, back, and finkes of a uniform black color. Lower 

 half or third of sides, the snout, lower third of forehead and pectoral 

 fins pure white. The two colors meet abruptly on the sides and do not 

 commingle. A broad black spot on the upper posterior margin of the 

 pectoral fins (Bennett) ; sometimes absent (?). 



Teeth, f^. Bones of skull thin and light. Rostrum broad and flat, 

 extremity rounded off; the margins beveled in the distal half. Its 

 length slightly exceeds one-half the total length. Its breadth at the 

 middle exceeds one-fourth its length. Preuareal triangular area long 

 and but slightly concave. Intermaxilhe not touching in the median 

 line; most widely separated distally. Central part of mandibular 

 symphysis raised above the level of the inferior margin of the maudible; 



