27U Annals Entomological Society of America [Vol. XI, 



13a. Alydus eurinus var. obesus n. var. { = A. pluto auct. in part). 

 Black, punctate, moderately pilose; pronotum tumid, about 3 mm. 

 wide; coritmi black or nearly so; posterior tibife usually black. Length 

 12 to 13 mm. 



Holotype: c? from Urbana, 111. Author's collection. 

 Allotype: Topotypic. Author's collection. 

 Paratype: 9 from Columbus, O. Ball collection. 



13b. Alydus eurinus var. eurinus Say, the typical form of the 

 species, is marked with fulvous brown on the corium, often mottled 

 with flavescent, the pronotum is flatter on the disc and not over 2^ or 

 2^4 mm. wide, and the posterior tibiae are fulvous brown to fuscous. 

 Length 10 to 12 mm. At the same time there is sufficient intergrading 

 to make it certain that only one species possesses the distinctive 

 genitalia. 



14. Alydus conspersus Montandon. 



Alydus conspersus Montandon (1893)'; Osbom (1894)2, (1900)^; Van Duzec (1894)^ 

 (1908)''; Heideman (1902)^ Wirtner (1904)'; Bueno (1905)», (1910b)^ Snow 

 (1907)"; Smith (1910)"; Barber (1911); Parshley {\my-. 



Alydus calcaratus Uhl. (1861); in error. 



Alydus rufescens, Barber (1911); ss below. 



Description. — -Head and anterior third of pronotum shining black, 

 finely punctate; pronotum with posterior two-thirds usually fulvous to 

 castaneous, occasionally darker, rarely black. Corium varying from 

 mottled fuscous and flavescent to nearly black. Membrane spotted 

 (var. conspersus) or infuscate (var. infuscatus) . Segments of antennae 

 varying in color and length, but fourth not exceeding second and third 

 together by more than one-eighth of their length; abdominal margins 

 and connexivum with pale segmental maculae or continuous rufescent 

 border. 



Male with claspers (Fig. S) divaricate at base, arcuate as seen from 

 the caudal aspect, convergent at tip, leaving an oval or pyriform 

 opening. Female with lateral plates of hypopygium (Fig. 7) with 

 mesal margins parallel and apices broadly rounded, mesal plates appar- 

 ently squarely truncate at tip. 



In Wisconsin and neighboring states A. conspersus is much 

 more common than eurinUs. It was originally separated from 

 the latter on the basis of the spotted membrane and greyish 

 to castaneous posterior two-thirds of the pronotum and these 

 characters hold for a majority of the specimens seen. The 

 strongly arcuate male claspers, surrounding an oval opening, 

 and the character of the lateral plates of the female hypopygium 

 which have their mesal margins subparallel and are broadly 

 rounded at the apex are, however, the only characters on which 

 complete reliance may be placed. 



