4. TTjRsio. 259 



ft. 



Length to the front of the dorsal .... 3 



Length to the end of the dorsal 4 



Length to the genital organ 5 



Length to the vent 5 



Length to base of tail 7 



Length to end of middle of tail 7 



Length to end of tail-fin 8 



There is some difficulty abont the colour of this species, which 

 may arise from two being confounded under one name. Bonnaterre, 

 Montagu, and Wright describe it as black above and whitish be- 

 neath ; 0. Fabricius as all blackish, the belly a little whiter, and 

 the young paler ; Schlegel figures it of a uniform deep black. 



The following are the measurements of five skulls, the first being 

 Montagu's specimen in the British Museum, and four in the College 

 of Surgeons ; the fourth is No. 1126, and the fifth No. 1125 of the 

 College Catalogue : — 



1. 2. 3. 4. 5. 



in. in. in. in. in. 



Length, entire 21| 21 21 21 22 



Length of nose 11| 12 12 11| 12 



Length of teeth-line 9| 10 10 10| 



Length of lower jaw 18| 18| .. 18 



Width at notch 5| 5 5| 5| 5| 



Width at orbits 10^ . . 10^ 10^ 9^ 



Width at middle of beak 3| 4^ 



In the skull of Montagu's specimen, in the British Museum, the 

 fourth and tenth teeth from the front on each side ajjpear, from the 

 hole, to have been larger than the rest. We have a second imperfect 

 skull of the same measurement. 



The skull of the skeleton presented by Mr. Howship, in Mus. CoU. 

 Surg. (n. 1125), taken below the Nore, in Jime 1828, has the 

 teeth |-|, the two hinder upper without any opposite them ; the 

 fourth, fifth, and sixth upper are largest, the middle lower are trun- 

 cated ; the lower jaw obHquely truncated, with a rather prominent 

 gonyx. The elongated intermaxiUaries and the vomer are ^asible in 

 the palate. In the old skuUs the intermaxiUaries are one-half width 

 above, and the sides of the maxillaries are shelving. In skull 

 n. 1126 (Mus. CoU. Surg.) the teeth are very obHque and truncated 

 at the end. 



In all the skulls I have seen of this species the teeth are more or 

 less worn down, but Mr. Bell says he has two skulls in which they 

 are acute (Brit. Quad. 472). M. F. Cuvier (Cetac. 223) complains 

 of Montagu's figure of the skidl of D. truncatus ; he does not recog- 

 nize in it the D. Tursio, but thinks it most resembles D. Delphis ! 

 hence the origin of his complaint. 



A stufted specimen and skeleton, in the Edinburgh University 

 Museum, from the Firth of Forth, have all the teeth truncated and 



s2 



