294 UNIVERSITY OF COLORADO STUDIES 



121 (122) Hyaline lamella rounded at distal end and not extended beyond end 

 of segment. Endopodite of right sth foot short. Length: male, 1.8; 

 female, 2 . o mm. Diaptomus claviceps Schacht 



La Junta, Boulder, Greeley: 4,100-5,400 ft. [Colorado, Iowa, Nebraska.] 



122 (121) Hyaline lamella with distinct angle at distal end or rounded at end 

 and extending beyond end of segment. Length : male, 1.7; female, i . 8 mm. 



Diaptomus leptopus Forbes 



All Colorado specimens seem to belong to the variety piscinae Forbes. The figures and distribution 

 refer to this variety. Boulder, Tolland; 5,400-10,950 ft. [Colorado, Montana, Manitoba, Alberta.] 



123 (103, 120) Antepenultimate segment of right antenna without appendage. 



124 



124 (125) Inner terminal process of second segment of left exopodite falciform. 

 Length: male, i.o; female, i . 2 mm. . . Diaptomus pallidus Hemck 



La Junta, Pueblo; 4,100-4,600 ft. [Lowlands of Mississippi Valley, Colorado.] 



125 (124) Both terminal processes of second segment of left exopodite digiti- 

 form. Length: male, 1.23; female, 1.38 mm. 



Diaptomus coloradensis Marsh 



Tolland, Kremmling, Mt. Carbon; 7,500-11,350 ft. 



126 (102) Antennae short (6-17 segments), never reaching beyond end of 

 cephalothorax. In male both antennae are enlarged and geniculate. Fifth 

 feet small and similar in male and female. Female carries two egg-sacs. 



FamUy Cyclopidae 

 Genus Cyclops 127 



Cyclops, like Diaptomus, forms a large part of the fresh-water Copepod fauna of all parts of the earth. 

 Unlike the latter genus, Cyclops includes relatively few species, nearly all of which have a very wide range, 

 many of them practically world-wide. Of the five species recorded from Colorado, only one, Cyclops ater, 

 is confined to North America. 



127 (133) Antenna of 1 7 segments 128 



128 (129) Fifth foot of one segment; armed with one spine and two long 

 setae. A large form; the female may be as long as 2.88 mm. 



Cyclops ater Herrick 



Greeley; 4,600 ft. [Rather widely distributed in United States.] 



129 (128) Fifth foot of two segments 130 



130 (131, 132) Second segment of 5th foot armed with seta and short spine. 

 Lateral seta of furca well toward end — at or beyond two-thirds of its length. 

 Several varieties, difiering chiefly as to stoutness. The more slender forms 

 are found in the larger bodies of water. Length of female, 1 . 5 mm. 



Cyclops viridis Jurine 



In all parts of state where collections have been made; 4,100-11,600 ft. [Widespread in Old and New 

 Worlds.] 



131 (130, 132) Second segment of sth foot armed with two setae — a long and 

 a short one. Lateral seta of furca not much beyond middle; a cluster of fine 



