130 TWELFTH ANNUAL REPORT. 



and long, ciliated setae; second pair longer and more slender, basal 

 portion forming two long oval joints; apical portion usually 4-6- 

 jointed. First four pairs of feet 2-branched, the outer branches 

 always three-jointed. Fifth pair either like the foregoing, or much 

 modified, unlike on the two sides, and in the male forming clasp- 

 ing organs. A heart is present. Eyes either median and stalked 

 or paired (lateral) and sessile; in the latter case being often coales- 

 cent and composed of several lenses. Sexual organs in the female 

 symmetrical, in the male asymmetrical. Ovisac single, borne in 

 front of [below] the abdomen. 



I. — Genus Heterocope, Sars. 



Cephalothorax 7-jointed; abdomen of female three-jointed; caudal 

 stylets short, with three large setas and other small spines. Anten- 

 nae long, slender, 25-jointed; right male antenna geniculate, the 

 six joints preceding the nineteenth swollen slightly, the previous 

 ones coalescent; external ramus of the antennules 7-jointed; labrum 

 tri-lobate; feet of the four anterior pairs with the inner rami one- 

 jointed; fifth feet of female with a single ramus, three-jointed, with 

 a terminal spine. The right foot of the male is cheliform, 

 four-jointed, second joint extending into a long cylindrical process, 

 the terminal joint with two apical claws. 



The writer is familiar with but three species — H. appendiculata, 

 Sars^ H. saliens, Lilljeborg, (= H. rubusta, Sars^) and H. alpiua^ 

 Sars. None of these have as yet been positively identified in 

 America* and their place seems supplied by the following genus. 



II. — Genus Epischura, Forbes. 



(= Scopiphora, Pickering?) 



Undoubtedly the most remarkable of fresh water copepods are 

 the two American species of this genus. It is not yet certain that 

 the second species may not be a young stage of the first but it seems 

 quite improbable. 



Related with Heterocope, Sars. The antennae are 25-jointed^ 

 the right of the male being geniculate. Tne thorax is 6-jointed» 

 the last two segments being partially coalesced. The abdomen is 

 five-jointed in the male and four-jointed in the female, one branch- 

 ed, in the male modified for prehension. Abdomen of male with a 



♦Heterocope is said by Patten (Cragen) to be common at Watertown, Conn. 



