286 ENTOMOLOGICAL NEWS [XXXI, '20. 



New Predaceous and Parasitic Mites of the 

 Superfamily Gamasoidea (Acar.). 



By H. E. EwiNG, Bureau of Entomology, U. S. Department 

 of Agriculture, Washington, D. C. 



The gamasoid mites of America have received but little- 

 attention from mite specialists, although the group is re- 

 presented by a fauna rich in species. Taxonomic difficulties, 

 especially in regard to the genera have been largely respons- 

 ible for this neglect. In the present paper eleven new species 

 are described. The writer has followed largely Banks' 

 interpretation of generic characters and his arrangement of 

 the genera found in America. Some of the predaceous forms 

 here described are of considerable benefit because of their 

 attacks upon injurious insects. 



Machrocheles bihastatus new species. (Text fig. i). 



A medium-sized, yellowish-brown species. Epistoma broad, rounded 

 and concealing the chelicerae when the latter are held in repose; on its 

 anterior border provided with a very long, sharp, central cusp and two 

 small, sharp, inconspicuous lateral teeth. Hypostome consisting of two 

 large, sword-like cusps that considerably surpass the central cusp of the 

 epistome. Chelicerae stout, heavily chitinized, ventral arm of chela 

 surpassing the upper arm and hooked around its distal extremity; both 

 arms provided with well-developed teeth. Body oval, evenly rounded 

 behind, and with shoulders well marked; clothed above with moderate 

 setae, a rather conspicuous pair being situated on the shoulders. An- 

 terior legs long and antenna-like; second pair stoutest and each provided 

 with a conspicuous spine which is situated on the outside of tarsus near 

 its tip; third pair distinctly smaller than adjoining legs; last pair extend- 

 ing slightly beyond the tip of body and with trochanters enlarged, being 

 much stouter than the femora and almost as large as the same. Posterior 

 coxae situated at the middle of the body. Length, 0.85 mm.; width, 

 0.50 mm. 



From near Lake Keuka, New York; in leaf mold from 

 gorge; by C. R. Crosby. 



Description based upon the type, a well-preserved female 

 specimen in the writer's collection, This species is quite 

 distinct from our other described American forms on account 

 of the large two-cusped hypostome. 



