1864.] DR. J. E. GRAY ON BRITISH CETACEA. 239 
Vertebrze 90 or 94. The atlas and axis only anchylosed; the rest 
of the cervical vertebree free. Scapula large. Thumb without a 
phalange. 
Skeleton, Mus. Bruxelles; Louvain ; at Mus. Copenhagen, Kiel, 
and Berlin. 
*** Beak moderate ; beak of the skull longer than the length of the 
brain-cavity ; teeth not reaching the notch. 
LAGENORHYNCHUS AcuTus. Eschricht’s Dolphin. 
Delphinus (Grampus) acutus, Gray, Spice. Zool. 2 (1828). 
Lagenorhynchus acutus, Gray, Zool. E. & T. 36, t.; Cat. Cetac. 
101. 
Phocena acutus, Gray in Brook’s Cat. 39, 1828. 
D. leucopleurus, var., Nilsson, Scand. Fauna, 598. 
Hab. North Sea. 
Delphinus (Lagenorhynchus) eschrichtii, Van Beneden, Nouv. 
Mém. Acad. R. Brux. xxxii. 31. 
Delphinus eschrichtui, Schlegel, Abhand. 122, t. 1, t. 2. f. 4, t. 4. 
f.5; M. Claudius, Dissert. de Lagenorhynchis, 4to, Kiliz, 1853; 
Eschricht, Compt. Rend. Acad. Sci. 1852, 12 July. 
Hab. North Sea; skeleton, Mus. Louvain. Faroe Islands (Schlegel) ; 
skeleton, Mus. Copenhagen, Leyden, Frankfort. Orkney (Brooks) ; 
skull in Mus. Leyden. 
The peculiar character of this species is, that there are 82 or 83 
vertebre ; the muzzle is narrower, the shoulder-blade narrower, a 
phalange to the thumb, the atlas and axis are anchylosed to the third 
and fourth cervical vertebrze by the spinous apophysis, and the sixth 
cervical alone has an inferior transverse process. Teeth i (Van 
Beneden, J. c. 31). 
Nilsson thinks my L. acutus may be only a variety of L. leuco- 
pleurus: the skulls are very unlike. 
b. Pectoral fins small, low down, and rather close together on the 
middle of the chest ; upper jaw toothless ; lower jaw with few 
teeth, sometimes deciduous. 
* Maxillary bones elevated into a crest on the sides behind ; teeth 
two or four, anterior conical ; eyes close to the gape. Uype- 
rodontina. 
4. Hypreropon. 
Forehead convex. Gape short, only as long as the short beak. 
The eyes near and the ears far behind the gape. The crest of the 
maxillary bone thin and wide apart above. The beak of the skull 
descending downwards. The hinder edge of the skull as high as the 
crest. Lower jaw rather curved. 
Bladebone triangular, with a long acromion and a posterior mar- 
