174 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.42. 



duced into triangular processes. The sixth or terminal segment of the 

 abdomen is as long as wide, 3 mm.: 3 mm., becoming gradually nar- 

 rower to an obtusely rounded extremity. The color and the markings 

 extend only about half the length of the segment, 

 the terminal half being white and semitranslu- 

 cent. The peduncle of the uropoda extends half 

 the length of the terminal segment; the branches 

 are long and narrow, with tapering extremities ; 

 the outer branch is 2 \ mm. long and extends 1 

 mm. beyond the tip of the terminal segment ; the 

 inner branch is not quite so long as the outer 

 branch and extends only one-half mm. beyond 

 the tip of the abdomen. 



The legs are all alike, prehensile, with long 

 curved dactyli, the basis not furnished with any 

 carina. 



Two adult females were collected at Fox Bay, 

 Colon, Panama, by Dr. S. E. Meek and Mr. 

 S. F. Hildebrand. They were parasitic on 

 Anchovia browni, being attached to the abdo- 

 men, midway between the base of the pectoral 

 and ventral fins. 



This species differs from the other known 

 species of this genus found on the Atlantic coast 

 of North America by its larger eyes, its much 

 longer terminal abdominal segment and much longer and differently 

 shaped uropoda. 



The types are in the United States National Museum. (Cat. No. 

 43350.) 



Fig. 1.— Livoneca longi- 

 stylis,new species. x 4f. 

 (Drawn by Miss V. Dan- 



DEIDGE.) 



