MEGAMCERA LONGIMANA. 
403 
AMPHIPODA . 
NATATOR1A . 
OA MM A RIDES. 
MEGAMCERA LONGIMANA. 
[Leach's Long-handed Screw.) 
Specific character. Second pair of gnathopoda having the propodos three 
times as long as broad, with the superior and inferior margins parallel, the 
latter finely serrated ; and the dactylos nearly as long as the propodos. 
Posterior pair of pleopoda having the rami sub-foliaceous and equal. 
Length y inch. 
Gammarus longimanus. Leach, MSS. in Collection Brit. Mus. Thompson, 
Ann. Nat. Hist. 1 ser. xx. p. 242. Nat. Hist, 
of Ireland, iv. p. 396. Spence Bate, Rep. 
Brit. Assoc. 1855, p. 58. Ann. Nat. Hist. 
2 ser. xix. p. 145. White, Hist. Brit. Crust, 
p. 184. Gosse, Mar. Zool. p. 141. 
Megamcera longimana. Spence Bate, Cat. Amph. Brit. Mus. p. 227, 
pi. xxxix. fig. 7. 
Gammarus Icevis. Bruzelius, Skand. Amph. Gam. p. 60, pi. ii. 
fig. 10. 
This animal is long and moderately robust. The 
inferior margins of the second and third segments of the 
tail are serrated. The eyes are round. The superior 
antennae are about half the length of the animal ; the 
inferior are much shorter. The first pair of legs are 
small, having the wrist and hand of nearly equal length. 
The second pair of legs have the wrist short and inferiorly 
produced to a point ; the lower margin is, moreover, 
