692 



FRESH-WATER BIOLOGY 



16 (15) Shell gland of ordinary form. . . Latonopsis fasciculata Daday 1905. 

 Post-abdomen with projections on dorsal (posterior) margin and 12-14 clusters of 2-3 lancet- 

 shaped anal spines. Color yellowish. Length, 9- to 2.0 mm.; ^ , to i.o mm. Louisiana, 

 Texas; in weedy pools and lakes. 



W 



I 



Fig. 1057. a, Latonopsis fasciculata; 

 b, Latonopsis occidentalis. 



Fig. 1058. a, Latonopsis fasciculata; b, Pseudosida bidentata. 



17 (14) Eye ventral or in middle of head. Rostrum present. 



Pseudosida Herri ck 1884. 

 Only one American species. . . Pseudosida bidentata Herrick 1884. 



General form like Sida but head more depressed and dorsum more arched. Rostrum present; 

 no fornix or cervical glands. Antennules attached as in Sida, long basal part with olfactory 

 setae on side, and long flexible fiagellum. Dorsal ramus of antennae with 2, ventral with 3, 

 joints; setae very unequal in length. Post-abdomen with about 14 clusters of spinules; claws 

 with 2 large 'basal spines and a very small spine proximal to them. 



$ with antennule of standard form; copulatory organs. Complex grasping apparatus on 

 first foot. 



Color yellowish, semi-transparent. Length, 9 . to 1.8 or 2.0 mm.; ^ , 0.9 mm. Southern 

 states, in pools and lakes. 



0.5 MM. I 



Figs. 1059, 1058, b. P. bidentata. (After Foster. ) (.See also Fig. 1058.) 



