250 BULLETIN 54, UNITED STATES NATIONAL MUSEUM. 



All the legs are prehensile, terminating- in long, narrow curved 

 dactyli. There is a high carina on the exterior margin of the basis 

 of the last four pairs of legs; the height of the carina increases from 

 the fourth to the seventh, where it is extremely high." 



CYMOTHOA EXIGUA b Schicedte and Meinert. 



Cymothoa exigua SCHICEDTE and MEINERT, Naturh. Tidsskrift (3), XIV, 1883-84, 

 pp. 232-234, pi. vi, figs. 7-8. 



Localities. Panama; also Charles Island, between the Galapagos 

 Islands. 



Found in the mouth of Citharichtkys sordida. 



Body ovate, rather compressed, more than twice as long as wide 

 (9:4). 



Head moderately large, subtriangular, widely rounded in front, two 

 or three times narrower than the fourth thoracic segment (almost 2: 5), 

 manifestly wider than long (almost 7: 6), a little immersed, frontal mar- 

 gin incurved, widely rounded. 



Eyes distinct, moderately large, subtriangular or subrectangular. 

 First pair of antennae smooth, rather stout, extending with the last 

 article to the anterior angle of the first segment of the thorax, or to 

 the eighth article of the second pair of antenna?; they are composed of 

 eight articles. 



The second pair of antennae are smooth, or rather compressed, much 

 more slender than the first pair of antennas, and extend with the two 

 last articles to the anterior angle of the first thoracic segment; they 

 are composed of nine articles. 



The anterior margin of the first thoracic segment is straight, with 

 the anterior angles short and obtusely rounded; the sides of the 

 segment are straight. 



The posterior angles of the anterior thoracic segments are rounded, 

 those of the posterior ones truncately rounded. 



The epimera are incurved and rather long; those of the first and sec- 

 ond pairs are rather narrow, posteriorly a little dilated, obliquely and 

 rounded truncate; those of the third and fourth segments are rather 

 narrow, posteriorly a little narrower, obliquely and widely rounded; 

 those of the fifth and sixth pairs are rather wider, posteriorly very 

 much narrower (but little narrower in the young female), and obliquely 

 and widely rounded. The epimera of the first, second, and third pairs 

 do not reach by a great and gradually increasing distance the posterior 

 angle of the segment; those of the fourth pair do not reach by a small 



For the description of the male, female, and the young of the first and second 

 stages, see Schioedte and Meinert, Nat. Tidsskr. (3), XIV, 1883-84, pp. 238-244. 



& This species is included because the fish on which it is parasitic is found as far 

 north as the coast of California. 



