242 Transactions.—Zoology. 
fringe of hairs on the lower surface. First pair of gnathopoda with carpus 
and propodos subegual, straight, and densely clothed with long, feathery 
hairs. Second pair with the carpus long, straight, and flat on the under 
surface, which is fringed with a double row of similar plumose hairs; 
propodos tapering and hairy ; dactylos minute. Fourth and fifth pairs of 
pereiopoda longer and stouter than preceding pairs. Antepenultimate and 
penultimate pairs of pleopoda reaching to extremity of ultimate ; all three 
pairs fringed with short spines. Telson short, reaching to extremity of 
peduncle of ultimate pleopoda, and furnished with a few short spines. 
(No locality). Length :8 inch. 
Sub-tribe. Hyperidea. 
Fam. I. Hyperide, Spence Bate, Brit. Mus. Cat. Amphip. Crust. p. 287. 
Superior antenne, with a peduncle of three joints, and a variable 
flagellum. Inferior antenns, with a five-jointed (?) peduncle, and multi- 
articulate flagellum. ^ Gnathopoda more or less complexly subchelate. 
Four anterior pairs of pereiopoda subequal, normal. Three anterior pairs 
of pleopoda normal; three posterior pairs, broad, flat, and biramous. 
Integument thin and free from hairs. 
Genus _Themisto, Guérin-Méneville, Mém. de la Soc. d’Hist. Nat. 
de Paris, iv., 1828; Edwards, Hist. des Crust., iii, p. 84; Spence 
Bate, Brit. Mus. Cat. Amphip. Crust. p. 811. 
Cephalon transversely ovate.  Pereion not largely distended. Pleon 
slender. Eyes occupying the entire cephalon, dorsally separated. An- 
tenne subequal, as long as the cephalon is deep; superior pair having the 
flagellum not articulated ; inferior pair having the flagellum more or less 
articulated. Mandible having an appendage. First pair of gnathopoda 
short, tolerably robust; carpus not having the anterior margin inferiorly 
produced ; second pair having the carpus on the inferior angle anteriorly 
produced. First pair of pereiopoda having the carpus dilated; propodos 
narrow, and capable of being inflected against the carpus ; second pair like 
ihe first; third pair twice the length of the second; carpus very long; 
propodos longer than the earpus, fringed along the anterior margin with & 
comb-like series of teeth, and capable of impinging against the anterior 
margin of the carpus ; fourth and fifth pairs subequal, of the same form as 
the third, but not more than half the length. Three posterior pairs of 
pleopoda subequal, the last being the longest; rami double, lanceolate. 
Telson small, squamose. 
The above description is taken from Spence Bate’s catalogue, and from 
the examination of a great number of specimens I can vouch for its cor- 
rectness as far as females are concerned, from which indeed all the descrip- 
tions appear to have been taken. The males, however, differ in the 
