DOLPHINS 275 



Ttirsiops tursio, Fabricius,* (Plate XVII.) has the 

 upper surface lead colour ; under surface white. 

 Teeth, 23. Vertebrae: C. 7; D. (12) 13; L. 17; 

 Ca. 27 = 64. 



This the only satisfactory type of the genus is 

 apparently of universal range, specimens having 

 been recorded from our own coasts (rarely, how- 

 ever), North America, New Zealand, Seychelles. 



The size of this species is some ten feet, but it has 

 been recorded as reaching twelve. Van Beneden 

 mentions that of specimens captured at Arcachon the 

 colour was an intense black save for a white streak on 

 the ventral surface, which was greyer in the male. 

 The fcetus possesses 4-7 hairs on each side. 



The amount to which the cervical vertebrae are 

 fused varies. The two first appear to be always 

 united ; of the following ones, more or fewer are also 

 fused. Sir W. Flower has figured its external charac- 

 ters, t Mr. True | observes of this whale that its 

 eyelids are as mobile as in the terrestrial mammalia. 

 The name tursio is derived from Pliny, but there is 

 no sure ground for identification. The ingenious 

 Belon would derive " Marsouin " (a corruption of 

 " Meerschwein ") from tursio. But as Frederick 

 Cuvier justly remarks, "We may agree that it would 

 be difficult to place faith in specific analogies founded 

 upon such a system ! " 



* Fauna Greenland, 1780, p. 49. 

 t Trans. Zool. Soc., xi., PI. I. 



t " Observations on the Life History of the Bottlenose Porpoise," 

 Proc. U.S. Nat. Mus., 1890, p. 197. 



