AIJSTBAUAN' MAIiACOSTBACA. 259 



pereiopoda much deeper than those of the three posterior pairs. 

 Basos of posterior pereiopoda long-ovate, serrated on the borders ; 

 meros hroad, strongly convex, produced to an acute point at its 

 distal and posterior angle ; meros and carpus armed at their 

 distal ends with a few bristles. Fourth and fifth pairs of 

 pleopoda subequal ; sixth pair with the protopodite short and 

 broad, the rami broad-lanceolate, and armed along the borders 

 with about twenty bristle-bearing serrations. Telson triangular ■, 

 blunt, with three small teeth at the extremity, and a notch armed 

 with a single seta near the distal end of the inner border. 

 Port Jackson. 



454 Megamcera diemenensis. 



Megammra diemenensis, Haswell, 1. c, p. 266, pi. xi., fig. 3. 



First four segments of the pleon each with a pair of strong 

 spines on its posterior margin near the middle dorsal line. Eyes 

 renifonn. Superior antennse more than half the length of the 

 body ; first segment of the peduncle stout, as long as the cephalon 

 and the first segment of the pereion, second segment narrower 

 and longer ; third segment short ; flagellum longer than the 

 peduncle ; appendage short, of four articuli. Inferior antennae 

 with the peduncle nearly equal in length to the two first segments 

 of the peduncle of the superior pair ; flagellum shorter than the 

 peduncle. Anterior gnathopoda small; carpus and propodos 

 sub-equal, hairy; propodos irregularly ovate; palm straight, 

 oblique, undefined. Posterior gnathopoda large ; meros armed 

 behind with a short spine ; carpus short, closely applied to the 

 ' propodos ; propodos four times as long as that of the anterior 

 pair ; broad proximally, becoming narrower towards the distal 

 end ; dactylos curved, bent on the inner side of the propodos when 

 closed. First and second pereiopoda sub-equal. Three posterior 

 pairs very broad ; meros expanded posteriorly, and, together with 

 the carpus and propodos, serrated and armed with setae ; third 

 pair shorter than the fourth and fifth ; basos of fifth pair much 

 broader than that of the others. Eami of the posterior pleopoda 

 sub-equal, twice as long as the protopodite, foliaceous, armed 

 with setae, along the margins. Telson with the halves laterally 

 compressed, each terminating in two acute spines, and armed 

 with a few short setse. Length 9 lines. 



Tasmania. 



