1C0.2194. NORTH AMERICAN PARASITIC COPEPODS— WILSON. 



35 



Lernaeinae, new subfamily. 



Suhfamily characters of female. — Cephalothorax armed with soft 

 horns or processes, two, three, or four in number and unbranched; 

 trunk straight Avithout a sigmoid curve; genital segment enhirged 

 on the ventral surface, just in front of the vulvae, into a pregenital 

 prominence; Qgg cases short and sacklike, eggs multiseriate. Two 

 pairs of antennae, second pair uncinate; a pair of curved and spine- 

 like mandibles; two 



pairs of maxillae; one -^=:^- 



pair of maxillipeds; 

 swimming legs widely 

 separated with a fifth 

 pair close to the vulvae. 



Suhfamily characters 

 of male (genus Ler- 

 naea). — Body like that 

 of Cyclops, composed 

 of a cephalothorax cov- 

 ered with a dorsal cara- 

 pace, three free thorax 

 segments, a genital seg- 

 ment, and a three- joint- 

 ed abdomen; anal lami- 

 nae each armed with a 

 single jointed seta, more 

 than half the length of 

 the whole body. Anten- 

 nae and mouth p arts 

 like those of the female; 

 a fifth and often a sixth 

 pair of swimming legs 

 on the genital segment. 

 Parasites of fresh-water fig. a. — the male (left) and female (uiottt) cofe- 



r. 1 . 1 .• . 1 rODID LAHVAE OF LEICN AEA VAItl ARI f-IS : ACTUAL LENGTH 



nSneS eXClUSUeiy. of female, I.OO mm., INCLLDJ.NG TUE long ANAL SETAE. 



Ontogeny of yenus 

 Lernaea. — The genital protoplasm at the posterior end of the ovary 

 gradually forms onto long threads or fihunents, transversely seg- 

 mented into cells. These increase in size toward the anterior end of 

 the ovary, and as they pass into the oviduct the filaments break up 

 into their separate cells, each of which forms an egg. The Qggri pass 

 down the oviduct to its posterior portion, which serves as a cement 

 gland. Just before entering this portion they are fertilized, and 

 after entering they are covered with an egg membrane composed of 

 the cement substance. 



