20 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xx.iii. 



ARGYRESTHIA RILEIELLA, new species. 



Plate V, fig. 6. 



.l?y/yre,s//rt«»/m(/(mWALSiN(;HAM [not Haworth], Insect Life, III, 1891, p. 118. — 

 DuKKANT, Kept, of Entomologists, Can. Dept. Agricult., 1897, p. 202.— Dyak, 

 Bull. 52, U. S. Nat. Mus., 1908, No. 6459. 



Head, face, and palpi white; antenna^ aiinulated with golden l)rown. 

 Thorax white, patajrina dark golden brown. Forewings white, above 

 the fold strong!}^ suffused with golden brown especially toward apex, 

 which is ([uite dark; along the outer half of the costal edge is an 

 irregular sei'ies of ill-defined small darker brown spots intervened 

 with whitish. The dorsal edge below the fold is nearly inunaculatc 

 white until the middle of the wing, where it is cut off by a large 

 ill-detined dark l)rown patch, which crosses the fold and gradually 

 widens out and is lost in the dark portion of the wing. Hindwings 

 light ocherous fuscous. Legs white, tarsal joints tipped with brown. 

 Forewings with veins 7 and 8 separate and one dorsal vein absent. 



Alar ex2?anse. — 9 m m. 



7/aJ/?5rt7^.— Washington, District of Columbia (Riley), May, 1885. 



Type.^C^i. No. 9948, U.S.N.M. 



Lord Walsingham erroneously recorded the European Argyresthia 

 m.endica Haworth on the unique specimen in National Museum, which 

 I have now made the type of rileiella. The specimen is only in fair 

 condition, and 1 should not have described the species until more 

 material was on hand except for the correction of this record; it is 

 certainly distinct from mendica., a figure of which (Plate V, tig. 5) 

 I give for comparison, it being smaller, more slender winged, and 

 without the white costal markings characteristic of the European 

 species; this latter of course must be dropped from our faunal list. 



It is also quite distinct from conjugeUa^ which species it was sug- 

 gested it might be by Mr. H. Durrant, who, with Lord Walsingham, 

 had realized, that the determination mendica was probabl}^ erroneous.'* 



Rileiella is nearest to pedmonteUa^ but is a smaller, more shining- 

 species in which the costal part is darker and the dorsal part more 

 immaculate white than in pedmonteUa. It differs from all three spe- 

 cies by the absence of one dorsal vein in the forewing. 



Named in honor of the collector, the late Prof. C. V. Riley, to 

 whose special interest in Microlepidoptera we owe much valuable work 

 done by himself and others in this group. 



«Durrant, Kept. Entom. Can. Dept. Agricult., 1897, p. 202. 



