ISOPODS OF NORTH AMERICA. 



253 



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

 side slightly convex. 



"The eyes are of median size, placed a little behind the middle of 

 the head near the lateral margins. 



'The first pair of antenna? are thick and robust, eight-jointed, with- 

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

 without hairs 01 spines. The second pair of antennae 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 slightly emarginate; it 

 is longer than the fourth seg- 

 ment (5 :!), and only a little 

 narrower than the fifth (5:6). 

 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 dactyli, 

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

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

 pair is longer than broad (24 : 17). 



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

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

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

 longest, the three preceding being equal in length. The second pair 

 of pleopoda carry very long styliform processes. 



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

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

 rounded at its lateral and hinder margins, exactly twice as broad as 



Fio.262. CYMOTHOA CARAIBICA (AFTER BOVALLIUS). 

 a, DORSAL VIEW OF MALE, x |. b, SEVENTH LEG OF 



RIGHT SIDE. X 12. C, FOURTH LEG OF RIGHT SIDE. 



x 12. d, SECOND PLEOPOD. x 12. 



