52 



CRUSTACEA BRONCHIOPODA 



female mobile. The head sepai'ated by a deep depression 

 from the thorax. Cuticle with a polygonal pattern. 

 j3 A pair of ventral spines on posterior margin of carapace. 

 Scapholeberis, Sohoedler (Fig. 20). 



Fio. 20. — Scaphole- 

 beris mucronata, 

 female, x 25. 

 Oxford. 



y No spine on posterior margin of carapace. Simoeephaltis, 

 Schoedler (Fig, 10, p. 39) : the cuticle with a pattern of 

 parallel branching ridges. 



Fis. 21. — Moina rectirostris, female, x 24. Oxford. 



ii. First antennae of female long, mobile. Moina, Baird (Figs. 

 16,17,21): median eye absent. Posterior margin of carapace 

 without a spine. 



Fig. 22. — Bosmina sp., female, x about 

 80. Lake Con.stance. 



Fig. 23. — Acroperns leucocephalus, 

 X about 35. Oxford. 



