ABT.5. NORTH AMERICAN PARASITIC COPEPODS WILSON. 39 



LERNANTHROPUS RATHBUNI, new specieg. 



Plate 2, figs. 16-19 ; plate 3, figs. 20-22. 



Host and record of specimens. — Two females were obtained from 

 the gills of a hogfish, Orthopristis chrysopterus^ at Beaufort, North 

 Carolina, July 24, 1905. They are made types of the new species 

 with Cat. No. 54069, XJ.S.N.M. 



Specific characters of fetnale. — Cephalothorax subquadrangular, as 

 wide as the body, with broad lateral flaps, each of which projects in a 

 rounded lobe forwards and backwards. The sinus between the lobe 

 and the antennal area anteriorly is narrow and deep; that between 

 the lobe and the thorax posteriorly is broad and shallow. Anterior 

 and posterior portions of the dorsal plate about the same length and 

 width, with a broad sinus on either margin between them. The 

 anterior portion is gradually narrowed anteriorly to meet the cephalo- 

 thorax, without any lateral prominences or shoulders. The pos- 

 terior portion is obovate, strongly narrowed posteriorly, with a broad 

 sinus at the tip, through which can be seen the anal laminae and a 

 portion of the abdomen. The genital segment is much wider than 

 long and projects in a half circle on either side. The abdomen is 

 only half as wide as the genital segment and is two-jointed, the 

 joints of the same length and width. 



The anal laminae are broad ovate, flattened dorsoventrally, and at- 

 tenuate at their tips. The egg strings are attached to the sides of 

 the genital segment; they are the same width as the rami of the 

 fourth legs and a little longer than the entire body. 



The first antennae are attached considerably behind the frontal mar- 

 gin ; they are quite distinctly segmented, with seven joints. The second 

 antennae are of the usual pattern, a swollen basal joint and a strong 

 terminal claw. The second maxillae have a fairly stout basal joint 

 and a long and slender claw, which is bent into a half circle near its 

 tip, the basal portion being straight. Proximal to the curve on the 

 inner margin is a small tooth, between which and the tip are two 

 rows of minute teeth, one along each side of the inner margin. 



The maxillipeds are large and strong, the base of the claw being 

 considerably reinforced, but the claw itself is curved only a little. 



The first legs have a broad flattened exopod tipped with four large 

 spines and a fifth, much smaller one at the distal end of the outer 

 margin. 



The endopod is conical and ends in a sin,gie long slender spine; 

 the inner margin bears distally a row of minute teeth. Inside the en- 

 dopod is a single large spine. The second legs have oblong flattened 

 rami, the exopod tipped with a long spine, the endopod with three 

 spines of about the same size at the tip and two much smaller ones on 

 the inner margin. Inside the endopod is a small rounded knob. The 



