DESCRIPTIONS AND DETERMINATIONS OF SPECIES 35 



from the body like a fin. Pleurites of the fifth segment small and tooth- 

 like, with but one point, which also projects from the body laterally and 

 bears two very small hairs on the posterior margin. The spiracles are 

 all extremely small. 



On the ventral side segment two with a median pair of spines, seg- 

 ments three to seven with fourteen to sixteen spines. Genital plate small, 

 sharply pointed posteriorly. Gonapods with three very small hairs. Cau- 

 dad of each gonapod a group of two small and two large hairs, and at 

 the posterior angles of the ninth segment a group of three stout hairs. 

 Anterior lip of the vulva fringed. 



Resembling the female except for the smaller size, more pointed ab- 

 .15 mm., length of abdomen .55 mm., width of head .12 mm., width of 

 thorax .15 mm., width of abdomen .35 mm. 



Resembling the female except for the smaller size, more pointed ab- 

 domen, and the absence of the pair of long hairs on the posterior margin 

 of the seventh segment. Basal plate entirely divided, the two parts slen- 

 der and widely separated, parameres likewise slender, strongly outwardly 

 convex, and with knobbed tips. Penis small, apparently divided into two 

 pieces. 



NEOHAEMATOPINUS Mjoberg. 



Neohaematopinus Mjoberg, Arkiv. for Zoologi, vol. 6, no. 13, p. 160. 



Acanthopinus, ibid., pp. 160-161. 



Neohaematopinus Cummings, Bui. Ent. Res., vol. 3, p. 393, (1912). 



Antennae five-segmented, set very close to the anterior margin of 

 the head. Basal segment with the distal post-axial angle more or less 

 produced, and bearing a stout spine; or with this angle not produced, 

 but with a stout spine on the posterior margin of this segment. In the 

 former case the antennae of both female and male are similar in shape, 

 in the latter case the distal pre-axial angle of the third segment in the 

 male is more or less produced. Head extremely broad, narrower than 

 the thorax. Anterior pair of legs small, with slender claw ; middle and 

 posterior pairs subequal, larger than the first pair, and with stout claws. 



Abdomen with or without distinctly chitinized tergal and sternal 

 plates, usually with the second to seventh tergites and second to sixth 

 sternites with two rows of spines, the remainder with one. Pleural plates 

 present on the first to seventh segments. Posterior margin of the second 

 tergite in the male slightly emarginate, and with a closely set group of 

 spines of various lengths at each end of the emargination. 



This genus was established by Mjoberg for a single species, N. sci- 



