62 Trans. Acad. Sci. of St. Louis. 
eyes, enlarged at the posterior end, where two small simple hairs are 
situated, and extending forward to the anterior tubercle which bears 
a whorl of bristles like those of the body. A small single pair of eyes 
situated two-thirds the distance from the dorsal groove to the lateral 
margin. 
Abdomen not separated from the cephalothorax. Body two-thirds as 
broad as long, broadly rounded behind. 
Anterior pair of legs fully as long as the body; tarsus of leg I very 
slightly swollen, two thirds as long as the tibia; tibia not as long as the 
antepenultimate segment. Second pair of legs three-fifths as long as 
the anterior pair; third pair slightly longer than the second pair. Last 
pair of legs extending one-half their length beyond the posterior margin 
of the body; tarsus one-half as long as the tibia, not swollen; tibia 
slightly longer and narrower than the antepenultimate segment. All 
the legs clothed with hairs similar to those of the body. 
Length, 1.68 mm.; breadth, 1.00 mm. 
In moss. Collected by L. M. Smith at Marion, II]. 
TROMBIDIIDAE. 
Last segment of palpus transformed into a thumb, penultimate ending 
in one or two strong palpal claws; cephalothorax small and frequently 
partially concealed by the protruding of the anterior part of the abdo- 
men; eyes stalked; tarsi frequently swollen. Larvae parasitic upon 
insects. Adults usually predaceous. 
TROMBIDIUM Fabricius. 
Includes forms in which the palpus ends in a single stout claw. 
Two species. 
KEY TO SPECIES, 
Body black, with the legs red T. subnigrum. 
Body and legs red T. missouriense. 
Trombidium subnigrum N., sp. 
Yd NAY aN ate 
Alcoholic specimens very dark brown; legs lighter. 
Palpi about one-half as long as the anterior pair of legs; palpal claw 
long, stout and sharp; thumb of palpus not swollen and slightly surpas- 
sing the claw. With a double pair of eyes, two being situated on a 
single, short stalk on each side of the cephalothorax just above the 
anterior pair of legs. Just in front of the eyes is situated a transverse 
row of four straight, subequal bristles about twice as long as the eye 
stalks. 
Body broadest at the anterior end and narrowest at the posterior end; 
subtruncate posteriorly and very sparsely clothed with simple hairs. 
Anterior pair of legs slightly longer than the body; tarsi swollen and 
thickly clothed with fine hairs, somewhat shorter than the tibia; tibia 
slightly longer than the antepenultimate segment. Second and third 
