KEY TO THE ENTOMOSTRACA OF COLORADO 



285 



85 (84) About 14 spines. Bristles extending little, if at all, beyond margin 

 of post-abdomen. Abdomen broadly rounded at end. A row of fine spines 

 at base of claw. Shell less arched than in preceding species. Length, 

 i.omm Alona af finis (Leydig) 



Tolland; 8,100-11,185 ft. [Common in America and in Old World from the extreme north southward. 



86 (83) Post-abdomen angled and armed with spines only (8-10 in number). 

 Form of shell much like reticulata. Length, 0.4 mm. Alona guttata Sars 



Probably equivalent to A . glacidlis Birge, reported from Greeley: 4,600 ft. (Widespread in New and 

 Old Worlds.) 



Fig. so. — Alona reclanguta. 



Fig. 52. — Alona guttata. 



87 



90 



(80) Free posterior margin of valves decidedly less than greatest height 



of shell 88 



(99) Outline of body as seen from the side, somewhat elongated . . 89 

 (90) Marginal spines of post-abdomen inconspicuous. Groups of very 

 small spines scattered on sides of abdomen. 

 Claw with single basal spine. A single curved 

 tooth at lower posterior margin of each valve. 

 Genus Dunhevedia 

 Only one species in Colorado. Dorsal mar- 

 gin of sheU much arched. Keel of labrum 

 not serrated. Length, 0.5 mm. 



Dunhevedia crassa King 



Probably the same as D. setiger Birge. Boulder, Tolland; 

 5,400-8,675 ft. [United States, Europe, Australia. Wide- 

 spread but not common .1 



(89) Marginal spines of post-abdomen of the usual type. Claw with two 



basal spines 91 



(96) Beak long and slender. In our species the shell is marked with stria- 

 tions that have a somewhat radial arrangement. . Genus Pleuroxus 92 



Fig. 53. — Dunhevedia crassa. 



