82 My. J. E. Gray on the British Cetacea. 
Mandibles nearly cylindrical, very long and prominent, widely 
divergent at the extremities, which are armed with a long, slightly 
curved dark brown fang, having a small, obtuse protuberance at 
its base on the upper side; on their inner surface are two rows 
of teeth, the outer one consisting of twelve and the inner one of 
eight ; they have, besides, seven strong tooth-like processes at 
their extremity surrounding the base of the fang: maxille long, 
straight, enlarged at the extremity, which is prominent and some- 
what angular on the outer side: these parts are yellowish brown. 
Lip semicircular and dark brown, the apex, which is prominent, 
being yellowish brown. Sternum of an elongated heart-shape 
and brown colour. Cephalo-thorax somewhat oval, slightly com- 
ressed before, broadly rounded in front, with a large circular 
indentation in the medial line of the posterior region; it is of a 
brown colour with rays of a deeper shade diverging from the me- 
dial indentation to the margins. yes disposed on black spots 
in two transverse nearly parallel rows on the anterior part of the 
cephalo-thorax ; the anterior intermediate pair, with each lateral 
pair, is seated on a prominence, the anterior eye of the latter 
being the smallest of the eight. Legs long, slender, provided 
with hairs and a few fine spines; they are of a pale brown 
colour ; first pair the longest, then the second, third pair the 
shortest. Palpi very slender and yellowish brown ; the cubital 
joint is the shortest and after that the axillary joint. Abdomen 
long, somewhat cylindrical, enlarged at its anterior and tapering 
to its posterior part ; along the middle of the upper part extends 
a large, festooned brown band whose margins are the darkest ; in 
the medial line of this band are numerous, minute, whitish spots, 
and four small indentations, forming an elongated trapezoid, 
whose anterior side is the shortest, occur on the part wah is 
enlarged ; sides dull yellowish brown, comprising an obscure, 
irregular, longitudinal brown band; under part dull yellowish 
brown, with a dark brown band in the middle tapering to the 
spinners, at the base of which, on each side, is a whitish spot. 
Spinners and plates of the spiracles reddish brown. 
XII.—On the British Cetacea. By J. EH. Gray, Esq., F.R.S. 
Havrne occasion lately to examine the various species of Cetacea 
in the British Museum and other collections and the various au- 
thorities for the species, I am induced to send you the following 
list containing some additions to our fauna. It would appear as 
though modern writers on this part of our fauna had not taken the 
trouble to examine for themselves the authority on which the spe- 
- cies have been determined. Dr, Fleming, in his ‘ British Ani- 
Pee ee 
