NO. 2354. NEW SPECIES OF PARASITIC COPEPODS— WILSON. 



pointed at the base, the median lobe considerably wider than the 

 lateral lobes and armed at each posterior corner with three large 

 spines. 



The transverse groove in the lateral area is situated far forward, 

 leaving the posterior portion of the area nearly twice as long as the 

 anterior. Eyes distinctly visible, rather far forward, small, and 

 fused on the midline. Free thorax segment as wide as the genital 

 segment, but only a fourth as long, covered with a pair of dorsal 

 plates, which overlap considerably the base of the genital segment. 

 The two plates are fused across the midline for the entire length of 

 the free segment, and then separated by a narrow sinus. Each is 

 semielliptical in shape, one-half longer than wide, with a strongly 

 convex lateral margin and a bluntly rounded posterior lobe, which 

 covers the basal third of the genital segment, and is entirely with- 

 out spines or armature of any sort. 



Genital segment half the width of the carapace, with strongly 

 convex lateral margins and long, flattened posterior processes. Each 

 lateral margin is armed with a set of stout spines which begin at the 

 center and extend backward nearly to the base of the posterior 

 process. The latter is narrowed posteriorly and is armed along its 

 inner margin with a row of small spines and three larger ones at the 

 tip. 



Abdomen two-jointed, the basal joint considerably larger than the 

 terminal and extending backward on either side of the latter in a 

 bluntly-rounded flattened process, similar to those on the genital 

 segment. 



Terminal segment with straight sides and carrying a pair of anal 

 laminae, each of which is long and narrow and tipped with four 

 plumose setae. 



The tips of the anal laminae do not quite reach the level of the 

 tips of the posterior processes of the genital segment. 



The second antennae have a stout basal joint with a slender ter- 

 minal claw, which is turned backward. The second maxillae have a 

 long and slender terminal claw, with an accessory claw at its base 

 on the outer side. The maxillipeds are short and stout with a blunt 

 claw. 



The swimming legs are similar to those of other species, the exo- 

 pods of the first three pairs being armed with the long curved pro- 

 cesses peculiar to this genus, one on the first pair, two on the second 

 pair, and three on the third pair. The fourth legs are reduced to 

 papillate, one-jointed stumps. 



Color (preserved material) dusky brown, deepening into black in 

 the thicker parts of the body. 



Total length, 10 mm. Carapace, 5.40 mm. long, 4 mm. wide. Free 

 segment, 2.15 mm. wide. Genital segment, 4 mm. long, 2.25 mm. wide. 

 Egg strings 5 mm. long. 



