68 Trans. Acad. Sci. of St. Louis. 



Mouth parts prominent. Palpi about one-half as long as the anterior 

 pair of legs; distal segment equal to the penultimate and well clothed 

 with hairs; antepenultimate segment stouter than the penultimate and 

 curved upward. Mandibles when extended as long as the palpi; chelae 

 subequal, slightly toothed and about as long as the last two segments of 

 the palpus. Epistoma and hypostoma apparently united to form a large 

 tubular structure containing the mouth parts; above this structure 

 shows three sharp cusps, one median and one on each side of this middle 

 cusp. 



Body almost twice as long as broad; slightly narrov^ed just in front 

 of the second pair of legs, subtruncate in front and rounded behind. 

 The body is sparsely clothed with moderate hairs and possesses a pair 

 of shoulder bristles and a pair of anterior marginal bristles. 



Genital opening of the male at the base of the hypostoma. Female 

 genital plate extending from the anterior margin of the coxa of leg III 

 to the posterior margin of coxa of leg IV. Anus in the case of both sexes 

 situated near the posterior margin of the abdomen. 



Legs slender; tarsi tapering. Anterior pair one and a third times as 

 long as the body; second pair of legs stouter than the others in the case 

 of both sexes and in the case of the male is provided with a large horn 

 in the shape of a spur (hence the name unicornutus) which arises from 

 the inner side of the femur. The tarsi of the last pair of legs are 

 especially long and are provided with longer hairs than the other seg- 

 ments. Tarsal claws of all the legs small and situated on long, slender 

 pedicels. 



Length of male, 0.70 mm.; breadth of male, 0.32 mm.; length of 

 female, 0.70 mm.; breadth of female, 0.40 mm. 



Found in moss. Collected by J. D. Hood on the Univer- 

 sity campus, Urbana, 111. 



Gamasus inagiiicornutiis n. sp. 



PI. X. f. 28. 



Yellowish brown; body darker than the appendages. 



Mouth parts large; palpi about one-third as long as the first pair of 

 legs; distal segment of palpus broader but equal in length to the penul- 

 timate; antepenultimate segment both longer and stouter than the 

 penultimate; palpi sparsely clothed with short, simple bristles. Epis- 

 toma of the male broad, with a shallow notch in the middle and two 

 short points on each side; hypostoma prominent. 



Body elongate, twice as long as broad, broadest at the insertion of the 

 last pair of legs. The entire upper surface of the body is corneous and 

 sparsely clothed with rather small, simple hairs. At the anterior mar- 

 gin of the body is situated a prominent pair of simple, curved bristles 

 about one-half as long as the palpi. 



Anterior pair of legs much longer than the others; tarsus and tibia 

 of leg I subequal, each provided with several rather prominent bristles. 

 The second pair of legs in the male are remarkable for their enormous 

 size, each being about one-half as thick as the body is at the point 

 where the legs are attached to it. The femur of the second pair of legs 



