THE WATER FLEAS (CLADOCERA) 



707 



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



Bosmina obtusirostris Sars 1861. 



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

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

 In pools and lakes; not rare; very variable. 



Figs. 1097, 1097, u. Bosmina obtusirostris. 



81 (80) Mucro longer than claws and process. 



Bosmina longispina Leydig i860. 



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. logS. 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 fiagellum. 

 Length, 9 , ca. 0.35 mm.; $ , 

 0.25 mm. 



Lake Charles and Calcasieu 

 Fig. 1099. Bosminopsis deitersi. Kiver, La. 



