NO. 1350. NATURAL HISTORY OF THE ISOPOD A— RICHARDSON. 35 



(1) In the entire concealment of the first abdominal segment on the 

 dorsal side ])v the last thoracic soo-ment; (2) in the much iarf^er epiniera 

 of the seventh thoracic segment, which are quite as prominent as those 

 of the sixth segment, and are somewhat broader, the posterior extremi- 

 ties not being on a level with those of the sixth segment, as is true of 

 i?. ociflttta, but extending some little distance behind; (3) in having 

 the propodus of the legs of the first pair armed with only four stout 

 spines, while in i?. ocvJuta there are eight, and in having two stout 

 spines, also, on the merus. while in R. ocuhita there are none; the legs 

 of the second and third pairs have three spines on the propodus, while 

 in R. (H'xhifii they have six spinivs; and (4) in not having the eyes pro- 

 duced posteriorly into lobes as in R. oculata. 



Family CIROLANID.E. 



CIROLANA JAPONENSIS, new species. 



Body about three times as long as wide, rather convex. 



Head transverse. Eyes very small, round, and situated at the 

 antero-lateral corners of the head. Color of eyes light brown. 

 Frontal margin of head with small median point, on either side of 

 which is a depression for the reception of the 

 antenna?. First pair of antennfe very short, reach- 

 ing only to the end of the fourth joint of the pe- 

 duncle of the second pair of antenna?; flagellum 

 with joints verv short and difficult to distinguish; ^^«- 3.-antenn^, fron- 



J • . . "^^"^ LAMINA, CLYPEUS, 



they number a])Out ten. Second pair of antenna? and labrum of ciro- 

 extend a little beyond the posterior margin of the ^^^^ japonensis, new 



. 1/11 • SPECIES. X 10. 



third thoracic segment; the flagellum contains 



about twenty-four joints. Frontal lamina or interantennal plate is 



narrow and elongate, this and the clypeus ))eing luiarmed and perfectly 



flat. 



The first segment of the thorax is not greatly longer than the 

 second, although it is a little longej-. The fourth, fifth, and sixth 

 segments are ecjual in length to each other and to the first, being 

 slightly lojiger than the second, third, and seventh. The epimera of 

 the second and third segments are not produced posteriorly. Those 

 of the following four segments are produced posteriorly, a gradual 

 increa.se in this feature being noticeable. The posterior extremity of 

 the epimera of the seventh segment reaches the posterior margin 

 of the second abdominal segment. All the epimera are ])road and 

 smooth, with only a faint trace of arched carina\ 



The first four segments of the abdomen are of equal width and 

 of nearly ecpial length. The third and fourth have the post-lateral 

 extremities produced. Th(^ fifth segment is eo\(M"ed at the sides by 

 the post-lateral prolongations of the fourth segment. The sixth seg- 



