274 



Illinois Natural History Survey Bulletin 



Fol. 23, Art. 1 



ed into two lateral humps; from this neck 

 there extends anterad a sclerotized plate 

 which terminates in a loop encircled b\' a 

 thin sclerotized thread apparently support- 

 ing a connecting membrane; apical portion 

 of aedeagus short, with a pair of thumblike, 

 baso-lateral projections and with the pos- 

 terior margin merging into a group of mem- 

 branous folds embedded in which are a pair 

 of stout sclerotized teeth. 



Female. — Similar in size, color and gen- 

 eral structure to male. Genitalia as in fig. 

 920. Eighth segment short and cylindrical, 

 sclerotized, the apex membranous and bear- 

 ing a crown of long setae, each set in a 

 conical membranous base. Ninth and tenth 

 segments more or less tubular, not distinct- 

 ly set off from each other, the tenth bearing 

 a pair of apical styles. Bursa copulatrix 

 complex, consisting of a series of mem- 

 branous folds and narrow sclerotized rods 

 at the attached end which culminate in a 

 highly ornamented, lantern-like structure to 

 which are attached two pairs of membra- 

 nous ribbons. 



Holotype, male. — Fort Davis, Texas: 

 April 19, 1939, along Limpia Creek, H. H. 

 & J. A. Ross. 



Allotype, female. — Same data as for 

 holotype. 



Paratypes. — Same data as for holotype, 

 26, 1$. 



Leucotrichia sarita new species 



This species may be distinguished from 

 the preceding by the longer claspers and 

 different shape of the eighth sternite. 



Male. — Length 4 mm. In color similar 

 to preceding species but without any con- 

 spicuous gray-green patch of hair on front 

 wings. General structure typical for preced- 

 ing species. Seventh segment without a 

 mesal projection. Eighth segment with ter- 

 gite fairly wide but much narrower than 

 sternite; sternite with postero-dorsal corner 

 produced into a large triangular lobe, ven- 

 tral margin transverse and indistinct on the 

 meson. Genitalia as in fig. 917. Ninth seg- 

 ment long and round dorsally and laterally, 

 but with the ventral margin almost com- 

 pletely open; postero-lateral margin bears 

 a row of long, stout setae. Tenth tergite 

 consisting of a pair of widely separated 

 sclerotized lobes between which are mem- 

 branous folds. Claspers fused, projecting 

 beyond the tenth tergite, each one bearing 



a long spine on its dorso-lateral margin. 

 Aedeagus consisting of a short base, a 

 heavily sclerotized neck which is thrown up 

 into a series of ridges and points, with a 

 pair of threads attached to base; apical por- 

 tion widening from base to apex, the tip 

 bearing a pair of sclerotized teeth embedded 

 in an expanse of membranous folds. 



Holotype, male. — Balmorhea, Texas: 

 April 19, 1939, along stone irrigation flume, 

 H. H. & J. A. Ross. 



Ochr atrichia weddleae new species 



This species is most closely related to the 

 genotype, insularis, described from Jamaica. 

 It differs from this species and all others in 

 the genus in the peculiar, short claspers with 

 their almost circular apical incision, fig. 922. 

 The simple type of tenth tergite indicates 

 a primitive condition similar to that found 

 in xena and unio. It is entirely possible that 

 this species is the most primitive yet discov- 

 ered in the genus. 



Male. — Length 2.5 mm. Color very 

 dark, almost black, the wings with a few 

 indistinct light areas and with a slight indi- 

 cation of a whitish line across middle. Gen- 

 eral structure typical for genus. 



Genitalia as in fig. 922. Ninth segment 

 short and stout, the lateral portion set of¥ 

 from the ventral by a curved distinct fold, 

 dorsal portion with a wide, U-shaped in- 

 cision almost to base. Tenth tergite set in 



Fig. 922. — Ochrotrichia w,eddleae, genitalia. 

 Male: A, lateral aspect; 5, dorsal aspect. 

 Female: C, ventral aspect. 



