THE WATER FLEAS (CLADOCKRA) 7,^ 



105 (104) Five to seven prc-anal spines; anlennary setae ordinarily ver>' long. 



Ilyocryptus spin if cr Il'errick 1884. 



:^'W 



Anus (.|K>ns in (lrpre\>ion oo 

 florsal margin of p(>%( al4<iontm; 

 <; 7 pre anal spinps; 4 8 |)i>s( aiul 

 lateral spines in ..:■ - - \n 



tt-nnary st-tar us»i. 

 timi's cqualint' Ir • , ^ 



in s<inu- sjxi : rt. 



apparently \>< .-ht 



til tt-n siimrii' : _ ip. 



Ilium fiitrnvil ami r^) 



$ unknown Cot ■.tl- 



(iish. Length. 9. • 



This siK-rics is / ir»; 



/. halyi Uraiiy. N • .'.n; 



Maine to Lake Suixriur an«! (.ulj 

 of Mexico l'rol»alily in .ill rriouns 

 of United States. 



FiC. 1 1 10. IlyocrypiHi ipinifn. 



106 (103) Anus at end of post-abdomen; molting complete. 



Ilyocryplus cicNlifrons SaTS i86i. 



0.1 MM 



Fig. nil. Ilyocryptus acutifrons. 



Post-abdomen not emar^i: '8 



small spines near claws, shor' iw; 



about () lonp, curved, lateral ; f 8 



marginal spines corresponding lo pre auaJ^ of 

 other species; the proximal two dirrttoJ for- 

 ward; from distal spine of this st-t a <(cric» of 

 vcr>' small marginals to anus, .\ntcnnulc club- 

 shaped, hairy. Ocellus nearer eye than inser- 

 tion of antennules. ("laws as in /. JorJiJui 

 Three to four summer eggs. S unknown 

 Color reddish or yellowish. I.trik'th. 9 f^- 

 0.7 mm. 



Rhode Island, Colorado 



107 (100, 116) Antennary setae 



0-0-1-3 

 1-1-3 



basal seta of 3-jointed ramus slout 



and stiff iU(/(-r(j///r/.v Haird 1843 



108 



Shape oval or rotund, somewhat compressed, with dorsal crest. Hca.l large, onlinarily noC 

 depressed; vertex evenly or abruptly rounded; rostrum short. \^'"!^^'' ."^•■»'^'" "f.^; '^ 

 ordinarily with long, stout, movable spines, which project in sc-yeral «i'rfvttons^ „" ^^TT 

 large; lateral sense hair near base. Antennae large; the proxmial sc-ta of ., jo.n cjl n»mu. onj. 

 stiff, and spinous; the others sparsely plumose or partly spmous. Hvc i;'"7; \"< " •;;*''• 

 dominal process. Post-abdomen large; often bilobed. ( laws small. InteMme s„npl. .>.. . .xa 

 $ with large antennules; hook on first foot. 



108 (115) Dorsal margin of head evenly roundeil. 



109 (114) Head extended; rostrum far from m 

 enlarged near distal end. 



irgin of valves, .\nlcnnulc5 

 110 



