THE WATER FLEAS (CLADOCKKA) 



190 (187) Rostrum not bent forward. 



191 (192) Numerous teeth along whole posterior margin. 



Plcuroxiis /run,. It 1,^ <( 



I-. Mullcr 



Posterior marKiii unn inm , 

 set teeth; valves striate! tli. 

 nearly longitudinal, tlie .,t)i, 

 men much like /'. tri>-ondius. >l,»{htiy'u- ■ 

 apex, an^le mu.Klecl; 12-14 marginal . Ic..'- 



Nebraska (Fordyce). 



Fig. 1 138. PUuroxus Irunai 



I F^urnj 



icati ^I«xlm«■n 



192 (191) Teeth at infero-posteal angle only 



193 (196) Post-abdomen long, slender, convex on ventral (upiK-r; side. 194 



194 (195) Supero-posteal angle sharp but not projecting- infcro-posteaJ 

 angle a sharp point J'laaoxus /iaslatt4s S^irs 1862. 



Infero-posteal anple a sharp point, with a vcn- snuill 

 tooth; valves reticulated, longitudinal marks oftrn m.,rr 

 distinct, givmg appearance of striation. if. 

 denticles. Color yellow, transjKirent ur 

 black unless ephippial. Length, 9. ca. o.f. : 

 0.45 mm. 



Rather rare; New England. Wisconsin. NcbnuJtA, 

 Caufornia. 



Fig. 1139. PUuroxus Auj/o/mj. 



0.1 MM 



195 (194) Supero-posteal angle overhanging; infero-po.^^teal angle rounded, 

 with small tooth in front of it. 



Plcuroxiis striiitHS SchtK-dler iS6j. 



General shape much likr T ' . • 



but never .so high archol as : 

 Valves obviously striatal. I'. 

 long, slender, with 20. or nmrt-. iiutrKiiiul 

 denticles. Color dark. rsjKHially oiU(jvie 

 on dorsal side, often nearly bUik. Length. 

 9. ca. o.S mm.; '. ca. of* mm. 



In all (Kirts of Cnitctl States; commoa 

 among weetls. 



This sjK'cies is /'. gradJis Hutlcndorf; 

 P. unidctts Birge. 



aiMM 



Fig, 1 1 40. Plfur>fXMs j/no/ni. 



