No. 2063. NORTH AMERICAN PARASITIC COPEPODS—WILSOy. 645 



Male. — Unknown. 



Type. — Tracheliastes polycolpus Nordmann. 



(TracTieliastes, Tpdxfj^dw, arching the neck like a horse.) 



Remarks. — This genus, Hke the subfamily, may be recognized at 

 once by the fact that the maxillipeds have migrated away from the 

 other mouth-parts, along with the second maxillae, t]x<^. two being 

 found together some distance behind the mouth tube. Nordmaiin's 

 figures and description were so convincing as to leave no question m 

 regard to the validity of the genus. It has never been disputed, nor 

 has it any syiaonyms like most of the other genera. Richiardi's 

 species, gigas, was simply named with only a few words of descrip- 

 tion, but the size given, combined with these few words, makes it 

 certain that he had a new species, and hsnce it has been included in 

 the following table: 



TABLE OF SPECIES. 



1. Cephalothorax half the length of the second maxillae or more 2. 



1. Cephalothorax less than one-fourth the length of the second maxillae 3. 



2. Size small (7.5 mm.); cephalothorax and second maxillae conical; the latter, 



together with the trunk, covered with rusty spots; genital process present. 



maculatus Kollar, 1835. 

 2. Size small (6 mm.); cephalothorax and second maxillae cylindrical and much 

 wrinkled; cephalothorax strongly arched; no genital process. 



polycolpus Nordmann, 1832. 



2. Size large (35 mm.); cephalothorax flattened and curved forward but not 



wrinkled; no genital process grandis, new species, p. 645. 



3. Size medium (12 mm.); cephalothorax short, cylindrical; second maxillae slender 



and tapering and not wrinkled; genital process present stellifer Kollar, 1835. 



3. Size large (80 mm.); mouth parts arranged like the sepals of a calyx; anterior third 

 of second maxillae filiform gigas Richiardi, 1880. 



TRACHELIASTES GRANDIS, new species. 

 Plate 40, figs. 106 to 108. 



Host and record of specimens. — Two females without egg strings 

 and with no label to indicate their host or locality were found in the 

 collection of the Museum. The better of the two has been numbered 

 43565, U.S.N.M., and is made the species type. 



Specific characters of female. — Cephalothorax relative^ very 

 minute, curved forward ventrally between the second maxillae and 

 much wrinkled; separated from the trunk by a deep invagination on 

 either side and by a dorsal and, ventral groove. Trunk massive, 

 strongly flattened dorso-ventrally, gradually enlarged toward the 

 center and then slightly contracted, the posterior margin almost 

 squarely truncated, with a slight invagination at the center and 

 rounded corners; no posterior processes, genital process, abdomen, or 

 anal laminae. The convolutions of the oviducts form a series of slight 

 rounded swellings along either side of the median line. These swell- 

 ings increase in size posteriorly and are of a darker color that the rest 

 of the trunk. 



