NO, 2194. NORTH AMERICAN PARASITIC COPEPODS— WILSON. 63 



Specific characters of female. — General form comparatively short 

 and stout; head bent forward at right angles to the thorax, with 

 four attachment plates at its anterior end, in front of the antennae; 

 a pair of long, branched lateral horns at the posterior end of the 

 head ; two other lateral and a posterior horn, all dichotomously 

 branched, on the thorax behind the fourth legs; thorax much widened 

 between the two sets of horns; neck comparatively thick, flexed 

 behind the horns and again Avhere it joins the body; trunk a short 

 ellipsoid, slightly flattened laterally; abdomen three-fifths the diam- 

 eter of the trunk and nearly the same length, somewhat enlarged 

 through the center; Qgg strings the same diameter as the neck and 

 longer than the trunk. 



First antennae minute, three-jointed, sparsely armed with setae; 

 second pair two-jointed and chelate; four attachment plates like 

 those in affixus, but each is deeply bilobed and the distal margins curl 

 over inwards. 



Maxillae small and three-jointed, the terminal claw short and 

 blunt; proboscis large and long, protruded from the ventral surface 

 of the head and parallel Avith tlie axis of the thorax; two large lateral 

 lobes at the tip, but no ventral plate visible; mouth-tube much 

 swollen between the lateral lobes, then abruptly contracted to less 

 than half the basal diameter; first three pairs of legs with a single 

 ramus indistinctly segmented, the fourtli legs without a ramus. 



Color (preserved material). — Neck and horns a j-ellowish cartilage- 

 gray; head red from the contained blood; body and egg strings a 

 brownish yellow. 



Total length, without egg strings, 12 mm. Length of head and 

 neck, G mm.; of trunk, 3 mm.; of abdomen, 3 mm.; of egg strings, 

 8.50 mm. Greatest diameter of the trunk, 1 mm. 



(poJyceraus, ttoXvs. many, and Kepas, a horn.) 



IiemurJcs. — Doctor Linton recorded in his notes that this species 

 was attached to the gill cover of its host and that the surrounding 

 tissues were congested and inflamed. The single gnatfish from which 

 his specimens were obtained was the only one examined by him, so 

 there are no data as to the abundance of the species. It will be seen 

 that this species resembles radiatus in the number and hardness of 

 its horns and affixus in the possession of attachment plates, but its 

 general makeup and the details of the appendages are quite different 

 from both. 



In general it may be recognized by its small size and its short and 

 stout trunk, the abdomen being as long as the genital segment. 



