Marshall—Ten Species of Arrenuri. 
147 
April until tiie first of December. They are found in small 
numbers in bodies of shallow still waters where Crustacea and 
water plants abound and where there is not too much, decom¬ 
position. Spring-fed pools where the water 1 is cold, like some 
of those at Big Springs in Adams County, flowing water, like 
the Wiseonsini River, deep waters like Devil’s Lake 1 , are not fre¬ 
quented by these mites. They are often found in ponds where 
there is great fluctuation in the depth of the water; in one in¬ 
stance they were found again when the pond filled after hav¬ 
ing dried up. They prefer the ooze at the bottom, as shown 
by the actions of those kept in aquaria. They are seen to* feed 
on small Crustacea. Dull blue green is the predominating 
eblor. They are not, very sensitive to drying, being protected 
by their thick skins. 
The females are most abundant in the spring, the males not 
appearing till late spring or summer. In the fall more males 
are collected than females. Eggs are laid in dense masses of 
from ten to forty, surrounded by a gelatinous; mass 1 . The 
young hatch in a week or ten days, but have not been kept be¬ 
yond the second larval stage. The adults are easily kept in 
aquaria,. 
There have already been described and recognized for the 
subgenus Megalurus the following species: 
Arrenurus adnatus Koenike, 
Art'enurus caudatus D ! e Geer, 
Arrenurus concavus Koenike, 
An'enurus conicus Piersig, 
Arrenurus corniger Koenike, 
Arrenurus coronator Thor, 
Amnwrus cylindratus Piersig, 
Arrenurus Dahli Piersig, 
Arrenurus geminus George, 
Arrenurus geniculalus Koenike, 
Arrenurus globator Muller, 
Arrenurus Koenihei Daday, 
Arrenurus Krameri Koenike, 
Arrenurus membranator Thor, 
Arrenurus Moebii Piersig, 
i 
