ON A NEW EPICARIDAN ISOPOD. 



527 



Length. Width. 



6th segment of mesosome, 0,237 mm. 0,746 mm. 

 7th „ „ „ 0,218 mm. 0,655 mm. 



Each segment of the mesosome has a pair of legs. The leg is 

 much like that of females in structure. As in these it is composed of 

 five joints exclusive of the coxal piece, of which the first, the second 

 and the fourth are larger than the third and the fifth. The fourth is of 

 an oval outline and forms a chela with the claw-like fifth joint. The 

 fourth joint shows at the proximal end a few (some seven or eight) 

 short tooth-like processes varying from 4 to 8/z in length. The third 

 joint has a few minute spinous processes near the distal end and a 

 single similar process near the middle. Measurements of the fourth 

 left leg of the male taken from the female specimen B are as follows : 



Length of the ist or proximal joint, 0,220 mm. 



Length of the 2nd joint, 0,160 mm. 



Length of the 3rd joint, 0,076 mm. 



Length (longest diameter) of the 4th joint, 0,196 mm. 



Length of the exposed claw of the fifth joint, 0,060 mm. 

 The metasome is small and not divided, all the segments com- 

 posing it being completely coalesced into a single plate-like urus. It 

 is of a triangular shape, attached with base to the mesosome. The 

 posterior end is obtusely pointed, and here the small anal opening is 

 situated. No appendages exist on the metasome. Along each side on 

 the ventral surface there stand at intervals three or four short hairs ; 

 besides, near the posterior end, there is a group of similar hairs. 

 Also on the dorsal surface hairs are present in similar arrangement ; 

 only a posterior group of them is wanting. (The cephalon and the 

 mesosome are also sparsely covered with hairs of the same kind.) 



The eggs are generally spherical in shape, though often modified 

 into polygonal as the result of mutual pressure in the brood chamber. 

 They measure on an average 0,168 mm. in diameter. They occur in 

 the brood chamber in a very large number. 



