Kev. A. M. Norman on new Crustacea AmpMpoda. 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 antennce short, about equal to peduncle of superior in 

 length, last two joints of peduncle subequal; flagellum not 

 longer than last joint of peduncle (about 8 articulations). 

 First gnathopods slender; wrist and hand parallel-sided, of 

 equal breadth throughout, both margins fringed with setae ; 

 hand shorter than wrist ; palm slightly oblique, finger slender. 

 Second gnathopods in ($ 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 setae ; finger stout, very strongly 

 curved, inner edge sparingly ciliated, closing with the palm 

 between the first and second tubercles, arching over and leav- 

 ing a space between its inner margin and the summit of the 

 distal tubercle ; second gnathopods in $ 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 jpereiojpods with the thigh (basos) 

 narrow and nearly parallel-sided, the distal joints strongly 

 spined, the claw strong and nearly straight. Pleon having 

 the infero-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) f inch, exclusive of antennae. 



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 Megammra of Mr. Bate from Mcera ; the depth of 

 the coxae 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 



