166 _ Trans. Acad. Sci. of St. Louis. 
35. ALONA INTERMEDIA Sars. 
Alona intermedia, Herrick & Turner, ’95, pp. 244-245; pl. LXII., 
fig. 15. 
This species was found on only one occasion; then it 
was in a marsh having a water temperature of 12° OC. 
The bottom was grassy, the grass was dead. 
36. ALONA CORONATA Kurs. 
Alona coronata, Herrick & Turner, ’95, p. 247. 
This form was found on only one occasion; then it was 
collected, in abundance, from a ditch in a marsh, in Jan- 
uary, 1908. 
PLEUROxUS P. E. Mueller. 
37. PLEUROXUS DENTICULATUS Birge. i 
Pleuroxus denticulatus, Birge, ’78, pp. 20-21; pl. I., fig. 21. 
Pleurozus denticulatus, Herrick & Turner, ’95, p. 256; pl. XLV., 
fig. 8; pl. LXIII., fig. 10a, 12, 13. 
Near Augusta, this species was common, among vege- 
tation, in certain marshes and no-outlet, permanent, 
ponds, having a water temperature from 8° C. to 17° C. 
38. PLEUROXUS HAMATUS Birge. 
Pleuroxzus hamatus, Birge, ’78, pp. 22-23; pl. II., fig. 13, 14. 
Pleuroxus hamatus, Herrick & Turner, ’95, p. 257; pl. LX., fig. 1. 
This species was abundant, among vegetation, in two 
of the large, no-outlet, permanent ponds; at a water tem- 
perature of from 16° C. to 21° C. 
cHypborus Leach. 
39. cHYDORUS sPHAERICUS O. F. M. 
Chydorus sphaericus, Birge, ’78, pp. 238, 24. 
Chydorus sphaericus, Herrick & Turner, ’95, p. 261; pl. LXIV., 
fg, 4) 9) 8, 30, 
This species was abundant in several of the no-outlet, 
permanent, ponds. It was found among vegetation and 
also where there was practically no vegetation. ‘The 
temperature of the water in which it was found varied 
from 10° C. to 29° C. 
