2. STENU — S. KOSTKATU.S AND PEKSnCILLATUS. 157 



STENO KOSTKATUS (Dcsmarest). 

 (Plate 6, figs. 1 ami 2.) 



Snout long, separated from the low forehead by a distinct coustrictiou. 

 Dorsal aud pectoral fins falcate. 



Color of the upper surfaces and fins purplish sooty black ; sides 

 marked with rather large stellate yellowish- white spots. Snout and 

 under surfaces of the body white, more or less tinged with purple and 

 rose-color, and marked with prominent purple spots. (Liitken.) 



Yetebr* : C. 7 ; D. 13 ; L. 15 ; Ca. 30 = G5. 



Teeth, H to ||j rugose. Skull massive. Eostrum long and com- 

 pressed, its breadth at the middle 11.5 per cent, to 18.8 ]jer cent, of 

 its leugth. Frontal plates of the maxilhe strongly bentj intermaxilke 

 convex, at wide opening between them opposite the maxillary notch. 

 Temporal fossie very large and rounded; pterygoid bones meeting in 

 the median line; vomer extending to the middle of the palate and visi- 

 ble in the median line ; mandible growing gradually axtenuated from 

 behind forwards, not keeled at the symphysis. Symphysis very loDg. 



Measurements of the slmll. — (British Museum No. 34Ga. Type of IS. 

 compressus): Total length, 51.1*^'"; length of rostrum, 3l'.5'=™; breadth 

 of rostrum at its base, O.S*^^'"; at its middle, 4,2""; breadth of intermax- 

 illiTi at same point, 2.9*="^; breadth between orbits, 16.4""; length of tem- 

 poral fossa, S.G^". (British Museum No. 345c. Type of S. frontatus): 

 Total length, 51.1""; length of rostrum, 3(K™; breadth of rostrum at 

 its base, 10.7*'"^; at the middle, 5.2*="'; breadth of intermaxilke at same 

 point, 3.0""; breadth across orbits, 19 3""; length of temiJoral fossa, 

 10.7*^^"^ (For measurements of the exterior see page 28.) 



Habitat. — Indian Ocean. Java. Atlantic Ocean; 1° 14' S. lat., 17*^ 

 20' W. long. {Liitken.) 



STENO PERSPICILLATUS Peters. 

 (Plate 7, fiys. 1 and 2. ) 



Form generally like Tursiops tursio. Beak distinctly separated off 

 from the forehead. Dorsal and pectoral fins falcate. 



Back black, belly white, sides of body and head yellowish white. A 

 milk-white stripe from the pectoral fiu to the eye. Eye surrounded by 

 a brown ring, from which a narrow brownish-black line goes forward 

 along the base of the forehead to meet its fellow on the opposite side 

 of the head. A similar line from the corner of the mouth to the base 

 of the pectoral fin. (Peters.) 



Teeth, I ; rugose. Vertebrte: C. 7; D. 12; L. 15; Ca. 32 = GG. 

 Skull like that of S. rostratus. (See p. 25.) 



Measurements of the exterior (From Peters). — Total length, 92.8 inches 

 (185"") ; extremity of snout to dorsal fiu, 3i.3 inches (82"") ; to pectoral 



