DELPHINIDiE. 79 



fourths of the rostrum and the corresponding part of the mandible, 

 are rather small, conical, and pointed, when unworn. The cranium 

 is rather narrow and elongated, and depressed ; the rostral is nearly 

 equal to the cranial portion in length, and is triangular, broad at the 

 base, and gradually narrowing to the apex, where it is sometimes 

 deflected. The cervical vertebrae are free. 



IBcIp^i^apt^ni^ leuca^ (Pallas^). 



Syn. Delphinus leucas, Pallas ^. 



Delphinnpterus heluga, Lacepede ^. 

 Beluga catodun, Gray *. 



Hab. Arctic Seas. 



46290. An imperfect sixth caudal vertebra ; dredged from the ISTorth 

 Sea. This specimen agrees precisely with the correspond- 

 ing vertebra of the existing form. 



Owles Collection. Purchased, 1874. 



Delphinapterus (?) brocchii (Balsamo-Crivelli'). 

 Syn. Beljjhinus hroccliii, Balsam o-Crivelli ^. 



The teeth are of great relative stoutness. The species is referred 

 to the present genus by Brandt in the Mem. Ac. Imp. Sci. St. Peters- 

 bourg, ser. 7, vol. xx. p. 241. 



Hah. Italy. 



47035. Pour teeth from the Lower Pliocene (Plaisancien) of Orciano, 



Tuscany, Italy. These specimens agree precisely with 

 the teeth figured by Capellini in the 'Mem. Ac. Sci. 

 1st. Bologna/ ser. 2, vol. iii. pi. ii. Purcliased, 1875. 



The foUoiuing specimens were associated ivith the preceding, hut indi- 

 cate smaller individuals ivhich, if helonging to the same species^ 

 must have been immature. The tympanies cori'espond in size 

 luith those of Lagenorhynchus acutus. 



47036. Two periotics and two imperfect tympanies. 



Purchased, 1875. 



^ Eeise etc. vol. iii. p. 85 (1776). — Lelphimis. 



2 Loc. cit. 3 jj-st_ -^^^ ^ Cetaces, p. 243 (1804). 



^ Zool. ' Erebus ' and ' Terror,' p. 29 (1846). 



5 Giorn. I. R 1st. Lombardo, vol. ii. p. 132 (1842), or vol. iii. p. 302 of 

 Giorn. e Bibliot. Ital. of same Society (1842). — Delphinus. 

 ^ Loc. cit. 



