156 Trans. Acad. Sci. of St. Louis. 



water varied from 16° C. to 21° C. The pond was about 

 ten years old and, in the shallow places, many plants 

 were found. 



The length of the female varied from 1.32 mm. to 1.57 

 mm. 



In addition to the Entomostraca mentioned in table I., 

 associated with it were hydrachnids, may-fly larvae, roti- 

 fers, snails, water-boatmen. 



Cyclopidae. 

 cyclops 0. F. Mueller. 



5. cyclops vikidis Jurine, var. brevispinosus Herrick. 



Cyclops brevispinosus, Herrick and Turner, '95, p. 95; pi. XXIII. , 



fig. 1-4; pi. XXIV., fig. 7-12. 

 Cyclops viridis, var. brevispinosus, E. B. Forbes, '97, p. 41; pi. 



XL, fig. 1-2. 



This form was found on only one occasion ; then it was 

 in a roadside ditch with a temperature of 15° C. 



6. cyclops viridis Jurine, var. insectus Forbes. 



Cyclops insectus, Forbes, '82, p. 649; pi. IX., fig. 6. 



Cyclops viridis, var. americanus, Herrick & Turner, '95, pp. 91- 



92; pi. XIV., fig. 1-9. 

 Cyclops viridis, var. insectus, E. B. Forbes, '97, pp. 41-44; pi. XL, 



fig. 3-6. 



In the neighborhood of Augusta, this form is widely 

 distributed; it is found in ditches, marshes, no-outlet 

 ponds and ponds with outlets. Where there is an abund- 

 ance of algae and other vegetation, this species is almost 

 certainly to be found. The temperature of the water 

 varied from 4° C. to 19° C. 



It is frequently covered with parasitic Protozoa, the 

 color of which is often green. 



7. cyclops viridis Jurine, var. ingens Herrick. 



Cyclops ingens, Herrick & Turner, '95, p. 92; pi. XXV., fig. 1-8. 



This variety was found in six localities ; but always in 

 either a flooded meadow, a marsh, or other temporary 



