TURSIOPS GILLII. 43 



TURSIOPS PAEVIMANUS Lutkcu. 



Tursiops 2iarvimanHS hiitken, K. Dansko Vidensk. Selsk Skr., Gfcli Rackkc, iv, 1887, 

 p. 354. 



Dr. Liitken has described under this name a small form, whicli is 

 closely allied to T. tursio. 



It differs chiefly iu having the tMrd digit longer than the second, with 

 more numerous phalanges. The formula of the phalanges is 2, G, 8, 3, 1. 

 The vertebral formula is as follows: C, 7 ; D., 13; L., 15; Ca., 27=G2. 

 In color the species is blackish on the back and fins, and grayish-white 

 on the belly. 



The species is founded on a single young individual from the Adri- 

 atic. A diagnosis is given in the second part of this work. 



TURSIOPS GILLII Dall. 



Tttrsiops (jlllii, Dall, Proc. Cal. Acad. Sci., v, 1873, p. 13; Scammon, Mariue 

 Mammalia, 1874, p. 288. 



This species was founded by Mr. Dall upon a single mandible, No. 

 13022, from Monterey, Cal.,* collected by Capt. C. M. Scammon. It be- 

 longed apparently to an adolescent individual. Although the mandi- 

 ble, as a rule, possesses no characters which will serve for the distinc- 

 tion of closely allied species, there is one in this case which seems of 

 value, namely, the comparative size of the condyles. In this mandible 

 the greatest diameter of the condyle is contained twice only in the 

 greatest depth of the ramus. In all the mandibles of T. tursio, on the 

 contrary, the greatest diameter of the condyle is contained two and a 

 half times in the greatest depth of the ramus. The comparatively large 

 condyles of T. gillii are found again in a skull of Tursiops, 51™' long, 

 from Lower California, No. 12051, collected by Captain Scammon. This 

 skull belonged to an aged individual; the sutures are largely obliter- 

 ated and the teeth are much worn. 



From its proportions alone this skull could scarcely be distinguished 

 from one of T. tursio, but the relations of the bones on the under surfaces 

 are decidedly different. In T. tursio the optic canal rises gradually to 

 the level of the antero internal border of the frontal, and the whole in- 

 ferior surface of the frontal is nearly plane. In T, gillii the optic canal 

 ends abruptly without reaching the level of the prominent rounded an- 

 tero-internal border of the frontal, which latter bone is deeply concave. 



In the wall of the temporal fossa of T. gillii the lower part of the 

 parietal appears as a narrow band between the anterior margin of the 



'Although this specimen is not marked "type" there can bo no doubt but that it 

 is the one from which the species was described. Mr. Dall, who kindly examined the 

 mandible at my request, could not decide whether it was his type or not, fourteen 

 years having passed since he last saw it. It corresponds, however, absolutely to 

 his measurements, and is furthermore, the only separate mandible of a Tiirsiops from 

 California iu the collection. 



