THE CANADIAN ENTOMOLOGIST. 317 



antennae long and slender, longer than the head ; head with a quad- 

 rangular tubercle between the eyes ; thorax slender, much narrower than 

 the head ; legs short and stout ; claws long and slender, as long as the 

 tibia and tarsus together ; tenant hair present ; furcula long and slender, 

 reaching the first pair of legs, densely covered with closely placed, blunt, 

 spiny tubercles, the tubercles arranged in transverse rows around the 

 spring, giving the spring a striated appearance with a low objective ; 

 manubrium short and stout, apex produced between the dentes broadly 

 triangular ; dentes long, slender, a few scattered hairs, and indications of a 

 transverse suture at middle ; mucrones short, pointed, with a triangular 

 tooth at base. Length, 1.25 mm. 



Habitat : Tennessee. 



Collected in great numbers by Prof. H. E. Summers from the surface 

 of thin, slimy mud. 



Pseudachorutes, Tullb. — Ocelli sixteen, eight on each side of the 

 head ; postantennal organ wanting ; antennae conical, four-jointed ; tarsi 

 with a single claw ; furcula short, reaching the apex of the abdomen ; 

 anal spines wanting. Type, Pseudachorutes subcrassus, Tullb. 



Brachysius,^ nov. gen. — Ocelli sixteen, eight on each side of the 

 head ; postantennal organ wanting ; antennas short, not longer than the 

 head is broad, four-jointed ; tarsi with a single claw ; furcula short, not 

 reaching the apex of the abdomen nor the ventral tube ; anal spines 

 wanting ; legs short and stout, not reaching the side of the body. Type, 

 Brachysius dilatatus, sp. nov. 



Brachysius dilatatus, sp. nov. — Bluish mottled with gray ; antennae 

 short, not much longer than the head, first joint very small, second and 

 third subequal, fourth almost as long as second and third together ; body 

 long and slender, broader towards the caudal end ; legs short and slender, 

 not extending beyond the side of the body ; furcula short and slender ; 

 anal papillae small, not divided, covered with stiff bristles. Length, 2 mm. 



Habitat : Ithaca, N. Y. 



This species has the habitus of those of the genus Neanura, but can 

 be readily distinguished by the number of ocelli and by the presence of 

 the furcula. 



Xenylla, Tullb. — Ocelli ten, five on each side of the head ; postanten- 

 nal organ wanting ; antennae four-jointed ; body cylindrical ; tarsi with a 

 single claw ; anal spines present, two. Type, Xenylla maritima, Tullb. 



§/3paxi's, brevis ; ra-o-ds. jaculum. 



