73J 



THE WATER FLEAS (CLADOCERA) 



213 (212) Post-abdomen short, broad; prc-anal an^lt- markc<I. 



214 (215, 216) Shell covered with deep polygonal cx-Ils. 



C/iyilorus fitviformis Birgc i8<;3 



Mmh like spharrifus in form and nizt X 

 unknown. ('(.lor yi-llow to lixht bruwnith. 



Lt-nKth, 9. 0.5 -0.0 mm. 



New Kn^'land, Wistunsin, Mkhiican. Ijuuiti- 



ana; nut common. 



Fig. ii4,S. Chy<L,rus /arifa 



cjukl tixU 



0.1 MM. 



215 (214, 216) 



Shell with deep polygonal ceils and ciiticular ridges. 



Clixdorus hiiornulus Doolilllc 



')Oi. 



0.1 MM. 



Like faviformis in havinp «lcfp pulygonal 

 cuticular cells; but (listinRuishf*! l»y the dr- 

 velopment of an extraonlinary ami fnmjJcJl 

 system of thin cuticular ridges, whiih cxtcixl 

 far beyond the ordinary cell>. .\ lon^j honi 

 extends laterally from the mi«ldlc dorsal rcKtun 

 of each valve, from which radiate v>mc of ihc 

 ridges. $ unknown. Color yellow. Ixni^h. 

 9. to 0.7 mm. 



Maine, New Hampshire, and New Jersey. 



I'IG. 1149. Chydorns buornutmi. (..Mler I>oQl*llr 



216 (214, 215) Shell of ordinary type -'' 



217(225) Ventral edge of keel of labrum smooth -»S 



218 (219) Antero-dorsal surface of valves and head flattened. 



Clivilorus i^ihhiis Ldljeborg livS 



iVSo. 



The cur\e of the flor«il surface somewhat ilat tend. 

 both in front and behin.l. making a M.rt of hump in 

 center of dorsal margin. X'alvi-s reticulatcl. \lr»d 

 small; rostrum projects from valves m chara.len^tK 

 wiv I'ost-abdomen with S 10 mannnal denUtic*. 



way 



Color yellowish to brown. I^-n>'th. 9 • o -S '"'"• 

 Lake Superior. WisconMM. Michigan; rare 

 This species is C ruguiosui lorl)e». 



Fig. 1150. Lkydorus cit^m. 



