THE WATER FLEAS (CLADOCERA) 



735 



233 (232) One to three rather strong teeth, valves reticulated. 



Alonella dentifera Sars 1901. 



Back high arched; infero-posteal angle acute, with 

 1-3 fairly strong teeth. Rostrum reaches nearly to 

 ventral margin of valves. Post-abdomen large, 

 broad, somewhat expanded behind anus; apex 

 rounded; with about 12 minute marginal denticles, 

 and as many very minute lateral fascicles. Claws 

 with i very long basal spine. Color yellow-brown. 

 Length, $> ca. 0.4 mm.; ,0.35 mm. 



Louisiana and Texas; not rare in pools and lakes. 



FIG. 1159. Alonella dentifera, with developing ephippium. 



234 (231) No infero-posteal teeth; form rotund. 



Alonella globulosa Daday 1898. 



Small; shape oval-rotund; head 

 reaching about to middle of valves. 

 Valves striated; all margins rounded 

 and without teeth. Post-abdomen 

 long, narrow; broadest near anus; 

 about 12 minute marginal denticles 

 and as many slender lateral fascicles. 

 Keel of labrum with 2 notches. 

 Color yellow-brown. Length, $> 

 0.30-0.4 mm. 



Lake Charles, Louisiana, among 

 weeds. 



This species is A . sculpta Sars. 



FIG. 1160. Alonella globulosa. 



2 35 ( 2 3) Post-abdomen with marginal denticles only 236 



236 (237) 



Denticles minute; post-abdomen large, bent behind anus; no in- 

 fero-posteal tooth on valves. Alonella diaphana (King) 1853. 



Head short, rostrum not reach- 

 ing more than two-thirds distance 

 toward ventral margin. Valves 

 striated, sometimes passing into 

 reticulation, often inconspicuous; 

 infero-posteal angle rounded, with- 

 out teeth. Post-abdomen long, 

 slightly enlarged behind anus; with 

 numerous very minute marginal 

 denticles and no other spines. 

 Claws long; i basal spine. Length, 

 ?, 0.5 mm.; $ , 0.4 mm. Color 

 yellow, transparent. 



Louisiana, Texas; in pools and 

 lakes; rare. 



FIG. 1161. Alonella diaphana. 



O.I MM. 



