NO. 1788. NORTH AMERICAN ERGASILID.^— WILSON. 329 



Nothing is said of the color of the specimens. 



Total length, 0.70 mm. Length of carapace, 0.285 mm. Width of 

 same, 0.25 mm. Length of egg-strings, 0.8 mm. 



(J'unduli, the generic name of the host.) 



A few specimens of this species were found on the gills of Fundulus 

 ocellaris {F. limbatus, Kroyer). 



The fish had been obtained near New Orleans, Louisiana, and sent 

 as specimens to the Royal Museum of Copenhagen. 



There they were examined and these parasites found and after- 

 ward sent to Kroyer. No specimens have been discovered since, 

 but neither have any of the Fundulus from that locality been exam- 

 ined for them. In all probability a little search would rediscover 

 this species and there would be a chance to find the male which is 

 as yet unknown. 



ERGASILUS LABRACIS Kroyer. 



Plate 41. 



Ergasilus labracis, Kroyer, 1863, p. 303, pi. 11, figs. 2, a to e. 

 Ergasilus labraces, Smith, 1874, p. 573. 

 Ergasilus labracis, Leidy, 1888, pp. 125 and 166. 



Female. — Body elongate, more than twice as long as wide, abruptly 

 narrowed posteriorly. Head completely fused with the first thorax 

 segment, with no indication of the union. 



Carapace three-fifths the entire length, projecting somewhat at the 

 center of the frontal margin, nearly squarely truncated posteriorly. 

 Free thorax less than half the width of the carapace, its segments 

 diminishing regularly backwards. 



Genital segment small, about the same width as the fifth segment 

 and half as long as the four free segments, with nearly straight sides. 

 Abdomen three-fifths as wide as the genital segment, three-jointed, 

 the joints about the same length but diminishing in width. Anal 

 laminae the same length as the last abdomen joint, each armed with 

 three setae, of which the inner one is very stout and twice the length 

 of the other two. Egg-tubes cigar-shaped, narrowed posteriorly, and 

 as long as the entire body; eggs in four to six longitudinal rows, 

 about twenty in each row. 



First antennae very short, hardly reaching the tip of the first seg- 

 ment of the second antennae, six-jointed, each joint as broad as long 

 and fairly well provided with setae of moderate length. Second 

 antennae half as long as the body, distinctly four-jointed; basal joint 

 short, swollen, and very obliquely truncated at its distal end; second 

 joint longer, narrower, and slightly curved, with a small knob at the 

 center of the inner border. The last two joints constitute the claw, 

 which is strongly curved and armed near the joint on the inner mar- 

 gin with several small knobs or teeth. 



