THE FAUNA OF BOULDER COUNTY, COLORADO 47 



Cephalothorax clearly separated from abdomen; female with two egg-sacs 



Cyclopidae. 

 Cephalothorax not clearly separated from abdomen; female with one or two 

 egg-sacs Harpacticidae. 



Family CYCLOPIDAE Burmeister 

 (147) Cyclops O. F. Muller is common in Colorado, but Dodds does not mention any 

 species from Boulder County, the material collected not having been determined 

 when he published his paper. Dr. C. Dwight Marsh informs us that he has C. 

 bicuspidalus Claus from Tolland, and C. serrulatus varieties montanus Brady and 

 elegans Herrick from Boulder. At Florissant I found a variety of Cyclops viridis 

 (Jurine), small and colorless, in a well which received its water from the Miocene 

 shales. Much water flows through these shales, and it is possible that the Cyclops 

 is essentially subterranean. I figure the fourth and fifth feet. In Biological 

 Bulletin, April, 1912, Mr. R. Chambers, Jr., has a very interesting article on the 

 forms usually regarded as varieties of Cyclops viridis, showing that certain of 

 them (americanus Marsh, parens, Herrick, and brevispinosus Herrick) have dis- 

 tinct chromosome numbers, armature of swimming feet and seminal receptacles, 

 and must be regarded as distinct species. 



Family HARPACTICIDAE 



Canthocamplus Westwood is represented at Greeley by C. minitlus (O. F. Muller), 

 as reported by Beardsley. It is very small; Beardsley gives length of female 

 0.65-0.75 mm., of male 0.60-0.65 mm - 



Soterfamily CALIGOLDEA (Isokerandria) 

 Family LERNAEOPODLDAE 



Parasitic on the gill-arches of fishes. Achtheres Nordm. is recorded from Colorado, 

 the species being A. carpenleri Packard. This was the first copepod to be reported 

 from our state. 



Order OSTRACODA 



Small Crustacea, the body consisting of very few (about eight) segments, and 

 completely inclosed in a carapace which has the form of a bivalve shell; develop- 

 ment direct, without a Nauplius stage (Geoffrey Smith). Mr. R. W. Sharpe has 

 discussed the American forms at some length in Proc. U.S. National Museum, 

 XXVI, XXXV and XXXVIII. The Boulder County species have not been 

 studied, but I give a synopsis of the Colorado genera based on Sharpe's tables. 



Family CYPRTDLDAE 

 Natatory setae shortened; no swimmers. Second foot with a beak-shaped end 



segment and a short claw Erpetocypridinae. 



Natatory setae reaching beyond end claws, or approximately to tips of claws. 



Second foot with a beak-like end-segment and a claw . . Cypridinae. 

 Natatory setae usually long. Second foot usually beak-shaped at tip, with a claw. 



Furca rudimentary, with a lash-like end bristle . . . Cypridopsinae. 



