6. TURSTO T. PERONII. 167 



Vertebi'iE: C. 7; D. Li; L. IS; Ca. ;J4 = 73. 



Teeth, % Skull small. Rostrnm very long (two tbirds the total 

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

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

 depressed. Temporal fossa', very small and rounded, their leugth equal 

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

 frontal. Zygomatic process of squamosal short. Palate with traces of 

 lateral grooves; vomer visible iu the median line. 



Measurements of the slciiU. — {Jo. 12, Mus. Pays-Bas. Type of D. 

 longirostris, Gray.) Total length, 42""; length of rostrum, 28"'; 

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

 orbits, 14""; lengtli of temporal fossa, 5"". 



Habitat. — Cape of Good Hope {ti/pe); between Panama and the Gala- 

 pagos Islands {U. 8. Hat. Mas.)-, Australia {Gopenharjen Mas.). 



G. TURSIO Wagler. 



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

 maxilhe flat. Pterygoid bones separate, the inner margins parallel. 

 Symphysis of mandible short. Teeth small, acute, and uumerous, 43 to 

 44. 



Head with a short, but distinct narrow beak (nearly iu the same 

 plane with the forehead iu L.^eronii). Ko dorsal Jin. Pectoral tins ftil- 

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

 sharply defined borders. 



TUESIO PERONII (Lac6p6de). 

 (Plato 21, figs. 1 and 2.) 



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

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

 Beak short, and nearly iu the same j)laue with the forehead. Lower 

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

 like those of Delphinus delphis. 



Upper part of head, back, and flukes 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 

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

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

 and but slightly concave. Intermaxilhie 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 mandible; 



