CETACEA. 117 



part of the skull of the latter is also rather more convex than the 

 same part in D. Pherusa. 



In the description of this species in the Zoology of the Erebus 

 and Terror, D. Metis is mentioned in three places instead of D. 

 Doris. 



13. DELPHINUS STYX. The STYX. 



Skull roundish, rather flattened behind ; nose rather depressed, 

 rather convex in the middle, shelving on each side, rather longer 

 than the head, f the entire length, nearly twice and a half as long 

 as the width at the notch ; the triangular impression just to the 

 line of the hindermost teeth ; teeth f f , slender, subcylindrical, 

 acute, about five in an inch ; palate nearly flat ; lower jaw rather 

 produced and rounded in front. 



D. Styx, Gray, Zool E. $ T. 40. t. 21, skull. 

 Inhab. W. Africa, Capt. W. T. W. Owen, R.N. 



Skull in Mus. United Service Institution. 



in. lin. 



Length, entire 18 



of nose 10 3 



of lower jaw. .. 14 9 



Width at the notch ... 46 



at the orbit .... 8 6 



Teeth f f 



This species is very like D. Euphrosyne, but is rather smaller 

 and the beak rather shorter : it may prove only a variety. 



14. DELPHINUS EUPHROSYNE. The EUPHROSYNE. 



Skull round, rather flattened behind; nose rather broad and 

 rather tapering in front, depressed, flat at the base, shelving on 

 the sides and rounded in the middle above, about half as long 

 again as the head, or f the entire length, and 2| times the length 

 of the width at the notch; teeth |f, slender, elongate, slightly 

 curved, acute. The iritermaxillaries are convex and rounded 

 above, with a wide groove between them for half their length in 

 front. 

 Delphinus Euphrosyne, Gray, Cat. Ost. Spec. B. M. 147 ; Zool. 



Ereb. fy Terror, 40. t. 22, skull ; Nilsson, Skand. Fauna, i. 595. 

 D. Styx, pars, Gray, Cat. Osteol. Spec. B. M. 38. 

 D. Holbollii, Eschricht, Naturf. mot i Kopenh. 1847, fide Nilsson. 

 Inhab. North Sea. 



in. lin. 



Skull, Mus. Norwich : Length, entire 18 6 



of head .... 74 

 of nose .... 11 3 



