KEY TO THE ENTOMOSTRACA OF COLORADO 



275 



rus bilobalus 

 Packard.) 



26 



-Lepidu- 

 (After 



(18, 19) Telson with i median and 4 paired dorsal spines. Segments 

 exposed back of carapace: male, 32; female, 28. Segments back of last 

 appendages: male, 14; female, 10. Length, 40 mm. 



A pus longicaudatus Leconte 



[Records of Hayden Survey from Colorado, Nebraska, Tesas, "near Yellowstone River.*'] 



(15) End of telson with a long paddle-like process. Genus Lepidurus 22 



(23) Process of telson notched at the end. Length: male, "including caudal 



stylets, 48 mm."; female, "length of body 



35 mm." . Lepidurus bilobalus Packard 



Po Canyon on Vermillion River, Colorado. 



23 (22) Process of telson not notched but 

 elongated and keeled. Length, 20 mm. 



Lepidurus couesii Packard 



[Montana and Utah. To be expected in Colorado.] 



24 (14) Carapace of two valves inclosing 

 body and appendages. 



Order Conchostraca 25 

 (32) Both head and body entirely inclosed within carapace. Carapace 

 with concentric lines of growth, resembling those of a moUusk shell. First 

 and second post-cephalic limbs prehensile in the male. 



Family Limnadidae 26 

 (27) Not more than 4 or 5 Unes of growth on shell. Frontal organ pedicu- 



lated. 18 pairs of feet. Branches 

 of 2d antenna 9-jointed. 



Genus Etdimnadia 

 Shell with 5 lines of growth. 

 Telson with 16 fine teeth on 

 dorsal side. 

 Length, 7 mm. 



Eulimnadia lexana Packard 



La Junta. [Nebraska, Kansas, Colorado, 

 I texana. (After Packard.) Texas.] 



-Lepidu- Fig. 

 (After Tus couesii. 

 Packard.) 



Frontal organ 



Id antenna 



Fig. ts.—Eulin 



27 (26) Shell with 18-22 lines of growth. Frontal organ not pediculaced. 

 24-27 pairs of feet. Branches of 2d antenna 15- to 20-jointed. 



Genus Estheria 28 



28 (29) Shell long and narrow. Umbones small and at about i length from 

 anterior end. Telson with many equal, fine teeth. Length, ii.o mm. 



Eslheria compleximanus Packard 



Ft. Collins, Montclair. [Kansas, Colorado, Lower California.] 



