THE WATER FLEAS (CLADOCERA) 



707 



80 (81) Mucro shorter than claws and process bearing them. 



Bosmina obtusiroslris Sars 1861. 



Frontal sense-hair near junction of antennules. Antennules shorter than length of valves. 

 Shell reticulated or smooth. Length, 9 , 0.3-0.5 mm. 



In pools and lakes; not rare; very variable. 



0.1 MM. - - j 



FIGS. 1097, 1097, a. Bosmina obtusirostris. 



81 (80) Mucro longer than claws and process. 



Bosmina longispina Ley dig 1860. 



Frontal sense-hair near junction of antennules. 

 Mucro and antennules long. Shell striated, marks 

 especially plain on head. Transparent. Length, 

 9 , ca. 0.4 mm. 



Rare, in lakes. 



FIG. 1098. Bosmina longispina. 



82 (77) Antennules united at base, and diverging at apex; numerous long 

 olfactory setae on their ventral side. 



Bosminopsis Richard 1895. 

 Sole American species Bosminopsis deitersi Richard 1895. 



In general much like Bos- 

 mina. Basal part of anten- 

 nules united with each other 

 and head to form very long 

 rostrum; diverging laterally 

 near apex, with long, strag- 

 gling, olfactory setae. Anten- 

 na with 3 -jointed rami. Post- 

 abdomen tapering to point at 

 claws; i large spine near 

 claws and several very mi- 

 nute spinules anterior to it. 

 $ with large movable an- 

 tennules; short rostrum; first 

 foot with hook and flagellum. 

 Length, 9 ca. 0.35 mm.; $ , 

 0.25 mm. 



Lake Charles and Calcasieu 



O.I MM 



FIG. 1099. Bosminopsis deitersi. 



River, La. 



