268 



Illinois Natural History Survey Bulletin 



Vol. 23, Art. 1 



EXTRALIMITAL TRICHOPTERA 



During the course of the foregoing study 

 of the Illinois caddis flies it has been neces- 

 sary to examine a large amount of material 

 from other states. Detailed studies of some 

 of the species involved have been necessary 

 in order to establish the species limits of 

 some components of the Illinois fauna. De- 

 scriptions of some of the more pertinent new 

 forms are presented here, partly to supple- 

 ment identification of Illinois species and 

 partly to supplement the check list. 



Rhyacophila banksi new species 



This species is unique among North 

 American forms in the narrow, angled and 

 bifid dorso-mesal projection of the ninth 

 tergite. Superficially it appears closely re- 

 lated to invaria but differs from this species 

 not only in the projection of the ninth ter- 

 gite but in many characters of the claspers 

 and tenth tergite. 



Male. — Length 10 mm. Color brown, the 

 wings without definite pattern except irreg- 

 ular spots of golden hair which occur over 

 most of the surface. General structure typi- 

 cal for genus. Genitalia as in fig. 908. 

 Ninth segment annular, narrowed ventrad, 

 and with a prominent dorso-mesal projec- 

 tion which angles sharply dorsad, is narrow 



Fig. 908. — Rhyacophila banksi, genitalia. 

 Male: A, lateral aspect; B, dorsal aspect. Fe- 

 male: C, lateral aspect; D, ventral aspect. 



at base, and expanded and distinctly emar- 

 ginate at apex. Tenth tergite with a promi- 

 nent pair of dorsal lobes which are produced 

 into a posterior point; below these is a cen- 

 tral style with a rounded apex and narrow 

 sinuate internal rodlike base. Claspers with 

 basal segment short and stocky, as wide as 

 long; apical segment almost as long as basal 

 one, apical margin very deeply incised to 

 form a large, rounded, dorsal lobe and a 

 long, rounded, ventral lobe, the latter with 

 a brush of short black setae on the mesal 

 face. Aedeagus very similar to that of in- 

 varia, having a short, stocky membranous 

 base with a mesal sclerotized body having 

 a wide, "eared" dorsal portion and a ventral 

 portion produced into an upturned sharp 

 point, flanked by an extensile membranous 

 lobe which bears a sclerotized, pointed blade. 



Female. — In size, color and general 

 structure similar to male. Eighth segment, 

 fig. 908, with ventral margin produced into 

 a tongue, divided at tip into a pair of nar- 

 row fingers; lateral margin sinuate and 

 dorsal margin deeply incised. 



Holotype, male. — Warren, New Hamp- 

 shire: June 21, 1941, Prison & Ross. 



Allotype, female. — Same data as for 

 holotype. 



Paratypes. — New Hampshire. — Pemi- 

 gewasset River, near Woodstock: June 22, 

 1941, Prison & Ross, 1^, 1$. Mount 

 Washington: June 22, in Tuckerman's 

 Ravine, P. Darlington, 2 $ , Mcz. 



Rhyacophila harmstoni new species 



The general structure of the genitalia 

 indicates a close affinity between this species 

 and vofixa; harmstoni, however, may be dis- 

 tinguished by the convex rather than con- 

 cave tenth tergite and the short aedeagus 

 with its two curved clusters of spines, fig. 

 909. 



Male. — Length 1 1 mm. Color various 

 shades of brown, the wings irrorate over 

 almost their entire surface. General struc- 

 ture typical for genus. Male genitalia as in 

 fig. 909. Ninth segment annular, slightly 

 narrowed ventrad. Tenth tergite short, the 

 apex divided into a pair of snoutlike reticu- 

 late lobes, the central and upper portion 

 convex, the dorsal angle produced into a 

 slight hump. Claspers wfth basal segment 

 stocky, longer than wide, its apical margin 



