i^l8.] OF THE UNITED STATES. 44I 



Found in the stagnant marsh water of the forests, in 

 the southern states. 



Genus CYCLOPS. 



Body elongated and attenuated behind; thorax abbre- 

 viated; eye one; antennce two to four, simple; Jeet six to 

 ten, hairy; (nil long, bifid. 



SPECIES. 



C. naviculus*. Body oval, attenuated behind; thorax 

 semioval, glabrous, rounded before, truncate behind, san- 

 guineous, hind angles acute; tail and feet white, the 

 former as long as the thorax, attenuated, terminal joint 

 bifid, seta four as long as the tail, the outer ones shorter, 

 two small equal spines at the base of each pair, and one 

 subequal one on the exterior side of the bifid part of the 

 tail, a little before the base of the seta; anterior antennas 

 two thirds the length of the body, spinose, white, extend- 

 ed each side horizontally, recurved, and more robust near 

 the base, and attenuated to the tip. 



Found in considerable numbers in stagnant fresh wa- 

 ter of the southern states. Swim by jerks, being alter- 

 nately at rest and in motion, the female carries her eggs in 

 two follicles, which are attached one on each side, near the 

 base of the tail, of the same colour as the thorax, and vast- 

 ly large in proportion with it, being nearly two thirds the 

 size. Eggs spherical, from twenty-five to thirty or more in 

 each follicle, consisting each of a dark nucleus and paler 

 border. 



