THE CRUSTACEA OF NEW JERSEY. 125 



Key to the genera. 



a. Bod}' slender, long, ends in swollen head with two or three simple curved 



horn-shaped appendages. lerneonEm.\ 



aa. Body broad, cyclops-like. with five distinct segments, of which first is 



large; head large, not beaked in front. Ergasilus 



Genus LERNEONEMA Milne-Edwards. 



Lerneonema Milne-Edwards, Hist. Nat. Crust., Ill, 1840, p. 524. Type 

 Lernconema lesneurii Milne-Edwards, first species. 



Body long', slender, narrowed anteriorly in form of neck 

 which ends by swollen head, furnished with two or three simple, 

 curved, horn-shaped appendages. Abdominal portion of body of 

 inconsiderable length, simple. Oviferous tubes long and slender. 



Lerneonema procera Leidy. 



Lerneonema procera Leidy, Proc. Acad. Nat. Sci. Phila., 1888, p. 165. 

 Beesley's Point, New Jersey (on Carcharias littoralis). 



Description. — Head horizontal, semi-oval, convex above, with 

 three short blunt occipital tubercles, fore part convex, excavated 

 beneath and closing mouth, antennas and maxillipeds. Neck 

 long, linear, cylindrical. Body short, fusiform, truncate behind. 

 Tail longer than body, linear, cylindrical. Egg-strings long, 

 linear and cylindrical. Color pale yellowish. Length 70 mm., 

 including egg-strings 90 mm. (Leidy.) 



Remarks. — Only known from the above account. Leidy's ex- 

 amples, apparently lost, were found attached to the mouth of 

 Carcharias littoralis, taken at Beesley's Point many years ago, and 

 still in the Academy. These lerneans were found hanging from 

 the upper lip on each side of the mouth, and were in turn them- 

 selves thickly parasitized by a hydroid, Bucope parasitica. 



\ 

 Genus Ergasilus Nordmann. 



Ergasilus Nordmann, Mikrog. Beitr., II, 1832, p. 7. Type Ergasilus sieboldii 

 Nordmann, first species, suggested by Wilson, Proc. U. S. Nat. Mus., 

 XXXIX, 191 1, p. 338. 



