THE WATER FLEAS (CLADOC'KR A'l 



224 (220, 223) About 0.5 mm. Antcnnule with one oli.ui..r% .. la j.r,,\:-: .,1 

 to cluster at end Chydorus aialu Kilrz xs-^^. 



0.2 MM. * 



Fig. 1 154. Chydorus ovalis. Entire specimen and 

 antennule. 



Form roun»l <.r Port- 



alMlomt-n with r. ij-i$ 



mar^'inal ricnticlr ' 'hiKawl 



si)in(-^. the proximal mmutc. ('f>k)r 



yellow. transjKirent I-rnKth. 9. to 

 0.0 mm.; ' <Kuro|K-ani, 05 mm. 



Rare; Nebraska. 



225 (217) Ventral edge of keel of labrum with one or more teeth. 



::6 



226 (227, 228) With several teeth; short spine at infcro-postcal angle of valves. 



Chydorus barroisi (^Richard) iS<>4. 



Form and size much like spkarruus. thoujch 

 ventral margin is lexs curved. Keel o( la- 

 brum acuminate behind: serrate, with (our or 

 more teeth. ro>t-alxlomen with well dcvd- 

 oped pre anal an«le; ia-12 marfrinal drnticlo. 

 shortest in middle of row. ( olor bruwnyd- 

 low. LenK'th, 9 . ca- ° 4 nim. 



Rare; Lake Charles. Ix)uisiana. 



Fig. II ss. Ckydorui tnirraul. 





0.1 MM 



227 (226, 228) With one tooth; infero-postcal spine present. 



' ^ ' Chydorus hvhndus Daday 



1005. 



Similar to barroisi but with only one tcxuh on keel o( Ubrum. 

 Rare; Wisconsin. .Micliican. Ixmisiana, FcxaA. 



Fic. 1 156. ChyJortu h)i>nJtu. 



