ART. 5. NORTH AMERICAN PARASITIC COPEPODS WILSON", 55 



Generic characters of male. — Cephalothorax relatively larger than 

 in the female, but having similar posterior lobes and styliform proc- 

 esses. Second and third thorax segments sometimes enlarged, fifth 

 and genital segments much shorter and narrower. Abdomen longer 

 and distinctly three-jointed, anal laminae long and armed with plu- 

 mose setae. 



Antennae, mouth parts, and swimming legs like those of the female, 

 the second antennae and maxillipeds being larger and stronger. 



Type of the genus. — Kr0yeria lineata P. J. van Beneden. 



KEY TO THE SPECIES. 



1. Abdomen of female containing but a single joint 2 



1. Abdomen of female two- or three- jointed 3 



2. Free thorax segments as wide as the genital segment ; the latter four times 



as long as wide acvleata (Gerstaecker), 1854 



2. Free thorax segments much narrower than genital segment ; the latter ten 



times as long as wide lineata P. J. van Beneden, 1853 



3. Genital segment the same width throughout its entire length ; abdomen with 



but two joints 4 



3. Genital segment considerably widened posteriorly ; abdomen three-jointed 5 



4. Cephalothorax nearly as wide as long ; styliform appendages reaching center 



of fourth segment ; anal laminae one-third the length of the abdomen, 



scylli-caniciili Hesse, 1878 



4. Cephalothorax only half as wide as long; styloforin appendages over- 



lapping the genital segment ; anal laminae two-thirds as long as the ab- 

 domen carchariae-glauci Hesse, 1878 



5. Styliform appendages reaching posterior margin of third thorax segment ; 



abdomen longer than genital segment galei-vulgaris Hesse, 1883 



5. Styliform appendages only reaching posterior margin of second segment ; 

 genital segment four times as long as the abdomen. 



acanthias-vulgaris Hesse, 1878 



Remarks. — This genus was established by Beneden in the refer- 

 ence given above and was placed in the family Caligidae, close to the 

 genera Trehius and Nogagus. In the following year Gerstaecker 

 described a closely allied parasite as a new genus and species, which 

 he named Lonchidvum aculeatum; In discussing its systematic affini- 

 ties, although the structure of the swimming legs showed affinity 

 with the Caligidae, Gerstaecker decided to place it with the Diche- 

 lesthiidae. 



In 1899 Bassett-Smith made the two genera described by Beneden 

 and Gerstaecker identical, but for some unknown reason adopted 

 Gerstaecker's genus name and made Beneden's name a synonym. 

 Brian in 1906 restored the name Kr0yeria and was followed in this 

 by T. and A. Scott in 1913. There is no doubt that their action is 

 correct and that the name given by Beneden should be retained. 



In the key given above the four species described by Hesse have 

 been retained, and are separated according to the distinctive char- 



