ISOPODS OF NORTH AMERICA. 



253 



downward in the middle; the anterior margin is rounded, the upper 

 side slightl}' convex. 



'•The eyes are of median size, phiced a little behind the niiddk^ of 

 the head near the lateral margins. 



"The lirst pair of antenna' are thick and robust, eight-jointed, with- 

 out distinction between the peduncle and the tiagellum, the last joints 

 without hairs oi spines. The second pair of antenna? are considera- 

 bly more slender, a little shorter, eight-jointed. The processes of the 

 first segment of the pereion are shorter and narrower than in Cymothoa 

 elegans^ rounded at the ends. The anterior margin of the first seg- 

 ment is slight!}' emarginate; it 

 is longer than the fourth seg- 

 ment (5 :-i), and only a little 

 narrower than the fifth (5:0). 

 From the fifth to the seventh, 

 the segments decrease in length, 

 but scarcely in breadth. The 

 seventh segment is longer than 

 half the sixth. The three first 

 segments together are as long 

 as the four last ones together. 



"The epimerals of the sec- 

 ond and third segments are 

 fixed along the whole length of 

 the segments, the following 

 ones only along half or two- 

 thirds of the length of the cor- 

 responding segments; all the 

 epimerals are equal in length 

 to their corresponding seg- 

 ments. 



' ' The first three pairs of pere- 

 iopoda have long, strong dacty li, 

 as long as the dactyli of the following pairs. The last four pairs have 

 strongly developed carinie on the femora. The femur of the seventh 

 pair is longer than broad (2-i:lT). 



"The pleon is broad, much broader at the base than long(5:;3). 

 The first segment is almost totally hidden, the pleon being a litth^ 

 more immersed than in Cymothoa elegans. The last is broadest and 

 longest, the three preceding being equal in length. The second j)air 

 of pleopoda carry ver^^ long styliform processes. 



"The urus is as long as the pleon, and only a little broader tiian the 

 last pleonal segment (12:11); it is smooth on its upper side, broadly 

 rounded at its lateral and hinder margins, exacth' twice as broad as 



Fig. 262.— Cymothoa cabaibica (After Bovallius). 

 a, Dorsal-view of male, x f . b, Seventh leg of 



RIGHT SIDE. X 12. C, Fot'RTH LEG OF RIGHT SIDE. 



X 12. rf, Second pleopod. x 12. 



