324 CUMADyE. 



sisting of a single scale-like joint, armed with a number of strong 

 spines ; the inferior antennae are five-jointed, being in general very 

 little longer than the rostrum. In Bodotria the superior antennae 

 are altogether obsolete, and the inferior antennae are very short. In 

 Alauna, again, we find the antennae more developed; the superior 

 consisting of a single-jointed peduncle, and a long multiarticulate 

 filament which is covered with hairs. The inferior pair are eight 

 or nine-jointed, and are somewhat larger than the rostrum. The 

 organs of the mouth consist of one pair of maxillae, three pairs of 

 mandibles, and two pairs of foot-jaws. These last organs will be 

 found minutely described under Cuma Edwardsii, the species which 

 I have been enabled to examine most minutely. 



" The true legs may be classed into compound and simple. The 

 compound legs, as we have already stated, are four in number in 

 the genera Cuma and Bodotria ; but six in Alauna. The first, 

 or compound legs, are divided into two parts, the anterior or am- 

 bulatory, and the posterior or natatory. The simple legs are much 

 shorter than the compound, and are more adapted for prehension ; 

 but they are unarmed with claws, and are seldom used for this 

 purpose. 



" The abdomen is moniliform, seven-jointed, in all the genera. 

 The last joint is very small in the genera Cuma and Bodotria ; 

 but in Alauna we find this segment very much developed. All 

 the genera have the sixth abdominal segment armed with a pair 

 of long bifurcated styles. The genera Cuma and Alauna are quite 

 free of appendages to the other abdominal segments ; but in < 

 dotria we find that all the abdominal segments are armed with 

 a pair of bifurcated appendages. 



" Owing to the opacity of the shell, I have not been able as yet 

 to make out the minute parts of the anatomy of these animals. 

 The intestinal canal consists of a long straight tube, considerably 

 dilated as it passes through the thoracic portion of the body; when 

 it reaches the abdominal portion it suddenly becomes much nar- 

 rower. 



" The anal aperture is found in the seventh abdominal seg- 

 ment. 



