August, 1944 



Ross: Caddis Flies of Illinois 



273 



dorsal portion, the sternite large and some- 

 what scoop shaped, and with a broad dorso- 

 lateral corner and a narrow sharp, V-shaped 

 mesal incision. 



Genital capsule as in fig. 915, retracted 

 so that the ventral portion is almost entirely 

 contained within the scoop-shaped eighth 

 sternite. Ninth segment with a large dorsal 

 tuft of long setae, not produced into an 

 internal lobe, the ventral portion almost 

 entirely cut away. Tenth tergite formed of 

 simple strap-shaped sclerites and possibly 

 including also the upturned sclerites at the 

 apex of the ninth segment. Near the junc- 

 tion of this sclerite and the ninth segment 

 are two long structures, a long, sinuate, 

 heavily sclerotized spine and a long, stout 

 seta on a long, filiform base, this seta as 

 long as the spine. Claspers fused on meson 

 to form a short, wide lobe. Aedeagus with 

 a small, cylindrical base, a convoluted semi- 

 membranous neck and with the apical por- 

 tion semimembranous at base, expanded into 

 a heavily sclerotized pear-shaped apical bulb 

 containing two internal sclerotized rods. 



LIMPIA 



Figs. 919-921. — Leucotrichia, female geni- 

 talia. J, lateral aspect; B, ventral aspect; 

 C, bursa copuiatrix. 



Female. — In size, color and general 

 structure similar to male. Eighth segment, 

 fig. 919, narrow and cylindrical with a 

 dorsal collar-like portion covered with short 

 setae, the ninth and tenth segments mem- 

 branous and simple. 



Holotype, male. — Missouri River, Tos- 

 ton, Montana: June 22, 1940, H. H. & 

 J. A. Ross. 



Allotype, female. — Same data as for 

 holotype. 



Paratype. — Same data as for holotype, 

 1 ?. 



Leucotrichia limpia new species 



This species is most closely related to 

 pictipes, differing from it in the gray-green 

 banding of the wings, the unmodified basal 

 antennal segments in the male and the 

 unique dorsal loop of the aedeagus. 



Male. — Length 4.5 mm. Head and body 

 dark brown, antennae slightly paler and 

 legs below coxae paler yet. Pubescence of 

 head, thorax and legs chiefly gray-green ; 

 wings dark brown, the front wings with 

 two large patches of gray-green hair, the 

 basal one occupying most of the basal two- 

 fifths of the wing, the apical one separated 

 from the first by the narrow black area and 

 covering half of the remaining length of 

 the wing. Structure typical for genus. 

 Ocelli present and close to mesal margin 

 of eye. Antennae filiform. Legs with tibial 

 spur count of 1-3-4. Hind wings with an 

 accessory row of hamuli across the radial 

 cell. 



Male genitalia as in fig. 918. Seventh 

 sternite with a small mesal point. Eighth 

 segment with tergite small, bearing a scat- 

 tering of long setae. Eighth sternite nar- 

 row above and widening to a broad ventral 

 sclerite incised on the middle, so that it 

 forms a pair of latero-apical subtriangular 

 lobes; the entire sclerite is clothed with a 

 scattering of fairly long setae. Ninth seg- 

 ment long and round dorsally and laterally 

 but almost completely open on the venter, 

 its apico-lateral margins bearing a row of 

 very long, stout setae. Tenth tergite com- 

 posed of a pair of sclerotized plates close 

 to the ninth and not projecting far posterad. 

 Claspers fused on meson, together forming 

 a spatulate projection and each bearing a 

 stout spine on the lateral margin. Aedeagus 

 very complex, consisting of a basal tube 

 articulating with the neck, which is expand- 



