MEGAMCERA SEMISERRATA. 
401 
A M PH TP ODA . GA MM A Rl DPS. 
NATATORIA. 
Specific character. Third segment of the pleon haying the inferior half of 
the posterior margin serrated. Eyes oblong. Second pair of gnathopoda 
having the propodos not broader than the carpus, ovate. Posterior pair of 
pleopoda with the rami equal. Telson double. 
Length | inch. 
Megamcera semiserrata. Spence Bate, Cat. Amph. Brit. Mus. p. 226, 
pi. xxxix. fig. 6. 
This animal is slender, and has the inferior moiety 
of the posterior margin of the third segment of the tail 
serrated. The eyes are small, and more reniform in shape 
than in any other species of the genus. The superior 
antennae are half the length of the animal, but the 
inferior scarcely extend beyond the peduncle of the su- 
perior. Both pairs of hands are nearly of the same shape, 
hut the second pair are larger than the first, and of a 
long oval form, having an oblique palm defined by one or 
two short spines ; the finger is short and serrated upon 
the inner distal half. The coxae of the anterior four 
pairs of legs are furnished with a single tooth upon the 
infero-posterior angle. The last three pairs of legs 
have the posterior margin of the thighs serrated. The 
posterior pair of caudal appendages reach far behind 
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