480 BULLETIIT 15 8, UNITED STATES NATIONAL MUSEUM 



Female. — Cephalothorax subspherical, as wide as long; a blunt 

 rostrum on the anterior margin; fourth segment two-thirds as wide 

 as the trunk ; the latter three and a half times as long as wide ; egg 

 strings one-fourth the width of the trunk and nearly twice the length 

 of the body. First antennae 3-segmented; proboscis as long as the 

 neck and narrowed distally ; basal plates of the legs with a notch on 

 the outer margin near the distal end. Total length, 7-9 mm. 



Remarks. — This species has not yet been found within the present 

 area, but Cape Ann is not far distant, and the host is a common fish 

 around Woods Hole, which makes it very probable that the parasite 

 will be found here soon. 



Genus LERNAEENICUS LeSueur, 1824 



Female. — Head fused with the thorax and furnished with slender 

 cylindrical horns, 2 to 10 in number, simple or branched ; thorax just 

 behind head enlarged and furnished with four pairs of legs close 

 together. Behind the legs the thorax becomes filiform and chitinous, 

 twisted and usually flexed for half the body length or more. It then 

 enlarges into a straight cylindrical trunk, and finally narrows into 

 an abdomen; caudal rami minute or lacking; egg strings filiform 

 and very long. Two pairs of antennae, second pair chelate; mandi- 

 bles without teeth; only one pair of maxillae, no maxillipeds; first 

 two pairs of legs biramose, third and fourth pairs uniramose, fifth 

 pair lacking. 



Male. — Unknown. 



KEY TO THE SPECIES (FEMALES) 



1. Head with 5 horns, cylindrical, chitinous, and branched or simple 2 



Head with 2 lateral, or 1 dorsal, horns, short and unbranched 3 



2. Horns arranged radially in a single set ; head in line with 



thorax; no attachment plates radiatus (p. 480) 



Horns arranged in 2 sets and branched ; head at right angles to 



thorax; 4 attachment plates polyceraus (p. 481) 



3. Two lateral horns; 4 attachment plates in front of antennae; 



abdomen much shorter than trunk afiixus (p. 482) 



One dorsal horn ; no attachment plates ; abdomen twice the 



length of trunk long'iventris (p. 483) 



LERNAEENICUS RADIATUS (LeSueur) 



FiGtniE 287 

 Lemaeocera radiata LESTrE:uB, Journ. Acad. Nat. Sci. Philadelphia, vol. 3, p. 



288, pi. 11, 1824. 

 Lernaeenicus Wilson, Proc. U. S. Nat. Mus., vol. 53, p. 59, pis. 4, 5, 1917. 



Occurrence. — Found with its horns buried in the flesh of various 

 parts of the body of the tomcod {Microgadus totihcod) , the menhaden 

 {Brevoortia tyrannies)., the mummichog {Fundulus heteroclitus) , the 

 eel {Anguilla rostrata)., the bluefish {Pomatoimis saltatrix)^ the 

 blueback {Pomolobus aestivalis) ^ the smelt {Osmerus mordax)^ the 



