52 CRUSTACEA—BRONCHIOPODA CHAP. 
female mobile. The head separated by a deep depression 
from the thorax. Cuticle with a polygonal pattern. 
8 A pair of ventral spines on posterior margin of carapace. 
Scapholeberis, Schoedler (Fig. 20). 
Fic. 20. — Scaphole- 
beris mucronata, 
female, eae 
Oxford. 
No spine on posterior margin of carapace. Svmocephalus, 
Schoedler (Fig. 10, p. 39): the cuticle with a pattern of 
parallel branching ridges. 
Fia. 21.—Moina rectirostris, female, x 24. Oxford. 
ii. First antennae of female long, mobile. Mozna, Baird (Figs. 
16, 17, 21): median eye absent. Posterior margin of carapace 
without a spine. 
Fic. 22,—Bosmina sp., female, x about Fic, 23.—<dAcroperus leucocephalus, 
80. Lake Constance. x about 35. Oxford. 
