114 SEVENTEENTH Report STATE ENntTomMoLocist or MINNEsSoTA—1918 
plumed hairs on the tip, besides several small hairs. Mandibles re- 
tracted into a surrounding sheath. On the base of this sheath is a 
pair of large clavate spines, brush-like at the extremity. Legs slender, 
tarsi all normal, with two stout curved claws and a dorsal tactile hair. 
When engorged the larva becomes 0.8 mm long by 0.5 mm wide. 
Coxae II and III become widely separated as well as the posterior 
dorsal plate from the anterior dorsal plate. 
Eggs. Spherical 0.19 to 0.20 mm in diameter; outer shell smooth ; 
color scarlet. 
Adults collected at many points in Hennepin, Carver, Ramsey, and 
Washington counties, Minnesota, probably found in all parts of the 
state where conditions are suitable. 
This species was named for me by Ewing as Allothrombium 
pulvinus, with the statement that his description was still in manuscript. 
It is extremely common in certain regions of Minnesota. What is 
probably the same species is mentioned by Riley and Johannsen (1914) 
as occurring about Ithaca, N. Y. It is the largest of our Minnesota 
species. The color is a dull scarlet, as if they had traveled over dry 
dusty soil and marred the original brightness of their velvety scarlet 
coats. On rocky or gravelly river banks where there is a great deal 
of undergrowth and where the soil is covered with fallen leaves they 
are especially common. They are seldom found close to the water’s 
edge, but usually high up where the soil is dry. They are also found 
along the edges of woodlands where the growth is scrubby and even 
along the edges of cultivated fields. During the last spring, however, 
quite a few were taken in a low, wet, marshy flat along the banks of 
the Minnesota River in company with Sericothrombium scabrum, Eu- 
trombidium locustarum, and Microtrombidium magnitarse. Because 
of its abundance fairly complete observations were made on this 
species. 
Adults appear in late summer and autumn, i. e., from late August 
to late October. During this time they are active during mid-day hiding 
in the soil and leaves at night time until a heavy frost appears, after 
which they bury themselves in the soil in a cell two or more inches be- 
low the surface. There they spend the winter until the frost is out 
of the ground and small forms of animal life become active. By 
April 1 they once more become active and may be seen on the search 
for food or preening themselves in warm spots of sunshine. In doing 
this the legs and palpi re curled beneath the body, the mandibles and 
palpi are rubbed with the front tarsi, then the legs are brushed and 
cleaned with any tarsus which is convenient. In searching for food 
