Rev. A. M. Norman on new Crustacea Amphipoda. 417 
ably longer than the first; third joint short, not more than 
one-fourth the length of the second; flagellum about equal in 
length to peduncle (22-24 joints); appendage 4-5-jointed. 
Inferior antenne short, about equal to peduncle of superior in 
length, last two joints of peduncle subequal; flagellum not 
longer than last jomt of peduncle (about 8 articulations). 
First gnathopods slender; wrist and hand parallel-sided, of 
equal breadth throughout, both margins fringed with seta; 
hand shorter than wrist; palm slightly oblique, finger slender. 
Second gnathopods in 8 very large; wrist triangular, short ; 
hand large, subquadrate, with an oblique palm extending one- 
third its length ; palm furnished with three well-marked tuber- 
cles, the distal tubercle flat-topped (or cup-formed?), sur- 
mounted by a circlet of sete; finger stout, very strongly 
curved, inner edge sparingly ciliated, closing with the palm 
between the first and second tubercles, arching over and leay- 
ing a space between its inner margin and the summit of the 
distal tubercle ; second gnathopods in 9 only slightly stronger 
than the first pair, and not differing greatly from them in 
structure; the hand, however, is ovate, the inferior margin 
gradually sloping upwards to the base of the finger, without 
having any defined palm; finger small, furnished with two 
spines near the end. Last pereopods with the thigh (basos) 
narrow and nearly parallel-sided, the distal joints strongly 
spined, the claw strong and nearly straight. Pleon having 
the imfero-posteal angles of second and third segments not 
serrate, but furnished with a single spine; dorsal margin of 
all the segments except the first toothed ; second segment with 
three, third with five teeth; fourth, fifth, and sixth with two 
teeth, each tooth having a spine at the inner side of its base. 
Uropods : first pair much longer than the second, but scarcely 
longer than the peduncle of the last ; last immensely developed, 
the peduncle long and very stout, the rami subequal, consist- 
ing of very long flattened blades, edged with and terminating 
in spines; the length of the entire uropod is nearly equal to 
that of the last six segments of the pleon taken together. 
Length (full-grown male) % inch, exclusive of antenne. 
Dredged off St. Martin’s Point, Guernsey, in 1864, by Mr. 
Jeffreys and myself. 
I can see no sufficient characters by which to distinguish 
the genus Megamera of Mr. Bate from Mera; the depth of 
the coxee is very variable in closely allied species. 
It will be seen from the preceding description that the female 
differs very materially from the male in the size and structure 
of the second pair of gnathopods. This is universally the 
case in the genus; and from a want of knowledge of this fact 
