ART. 25 INSECTS OF ORDER TRICHOPTERA — MARTYNOV 13 



ment subdivided by the median fissure into two lateral portions, 

 bearing hairs; their inner portions form two, nearly contiguous, 

 slender processes, directed backward. Side portions of the tenth 

 segment, seen from the side, form two subtriangular projections 

 above the side pieces of the ninth segment ; seen from beneath these 

 projections prove to be curved inward, in the shape of two trans- 

 vei-se narrow plates. Length of body, male, 11 to 12 mm.; female, 

 12.5 mm. 



Remarks. — This form differs from Psevdosteno'phylax fimiosus 

 from Ordos * by the dense brush of spines on the eighth tergite, by 

 the presence of but few hairs on the ninth segment, by Rs arising a 

 little earlier, bj^^ much more distinct reticulation in the anterior 

 wings, and by more slender and paler longitudinal veins. The shape 

 of the inferior appendages is somewhat varying. Position of Rsi 

 is also not quite constant, and there are some intermediate conditions. 



The structure of female genital segments recalls those of P. 

 szechwanensis Martynov. 



Type.— Male, U.S.N.M. No. 43160, from Uen Chuan, Szechwan. 



Specimens examined. — One male, from Mount Omei (5,000 to 

 11,000 feet), Szechwan, August 24-27, 1921; one male and one female, 

 from Yellow Dragon Temple, near Songpan (11,000 to 14,000 feet), 

 July 20-24, 1924; one male, from Uen Chuan, Szechwan, 1921. 



PSEUDOSTENOPHYLAX DIFFICILIS, new species 



Plate 3, Figubes 38 to 42 ; Plate 4, Figures 43, 44 



Description. — Head yellowish anteriorly, yellowish brown above; 

 vertex somewhat elevated, forming between the bases of antennae a 

 rounded prominence with a third ocellus at its apex ; hairs brownish, 

 mixed with yellowish anteriorly. Antennae brown, with yellow an- 

 nulations, basal joint yellow. Prothorax yellowish brown; mesono- 

 tum brown in the middle, almost black at its sides ; coxae brownish, 

 femora and tibiae yellow, the anterior and median ones with brown- 

 ish spots; tarsi yellow, but the bases and ends of the joints, except 

 the end of the fifth, are brownish ; posterior tarsi yellow, somewhat 

 brownish at their bases ; last tarsal joint with a few spinules ; spines 

 black. Anterior wings obliquely rounded at their apical margin; 

 apical portion comparatively large; ground color brown, irrorated 

 with very numerous small rounded pale spots; veins yellowish. In 

 the male C and R are very thick, in females more slender ; discoidal 



^ In Ann. Mu."?. Zool. Acad. Sci. St. Petersburg, vol. 19, p. 267, 1914, P. fumosiix ia 

 indicated from Soutli Siberia. I would note here that this indication is erroneous and is 

 based on an incorrect label. Both male specimens, mentioned there, were taken also In 

 Ordos, by N. Przewalsky. 



