AUT. 23 REVISION OF THE BEETLE GENUS OEDIONYCHIS BLAKE 33 



explanate margin ; pale yellow, usually immaculate, but in darker 

 forms sometimes with obscure darker spots or even piceous spots 

 united in form of an irregular fascia; very faintly and sparsely 

 punctate. Scutellum small, reddish brown or piceous. Elytra 

 broadly oval, feebly convex, sides distinctly arcuate, with broad, 

 often reflexed, explanate margin, humeri small, short basal sulcus 

 within; pimctation coarse, moderately deep; elytral markings very 

 variable, frequently pale yellow brown, usually with median reddish 

 brown or dark brown vitta not reaching base or apex and of varying 

 length, often a spot on humeri elongated sometimes to a lateral 

 vitta extending half length of elytron, frequently a short vitta at 

 base near suture, usually not extending more than one-third length of 

 elytra, these vittae often in part disappearing or occasionally widen- 

 ing and uniting to cover most of elytra with only yellow streaks 

 between and paler margin ; a form with reddish brown elytra with- 

 out vittae having somewhat paler margin; sometimes entirely piceous 

 Avith pale margin. Body beneath finely pubescent, yellow brown, 

 usually with meso- and metasterna and abdomen dark brown, often 

 last ventral segment pale, epipleura pale. 



Length. — 3.5 to 5 mm. ; width 2 to 2.5 mm. 



Type locality. — Not given. 



Distribution: — Quebec, Maine, Vermont, New Hampshire, Massa- 

 chusetts, Rhode Island, Connecticut, New York, Pennsylvania, 

 Illinois, Iowa, Wisconsin, Ohio, Michigan, Maryland, Virginia, West 

 Virginia, North Carolina. 



Horn, who first described this species as a variety of Oe. limhaUs, 

 wrote that the striped form seemed the more abundant and that it 

 was remarkable that it had not received a name. Examination of 

 the specimens in Horn's collection labelled Oe. limbalis shows no 

 specimens corresponding with Melsheimer's Ihnhalis. Horn's lim- 

 halis, in other words, is the dark form of his variety subvittata. 

 Oe. subvittata, Horn writes, is the most broadly oval species in our 

 fauna. The head is broad, with wide interocular space, the pronotum 

 is nearly three times as wide as long, the elytra are rounded with wide 

 explanate margin. There are, as Horn also remarked, fewer dark 

 forms; in fact, the black form with pale margin is rare. More 

 frequently the subvittate form becomes reddish brown with more 

 or less indistinct vittate markings. Sometimes the vittae are not 

 discernible, at other times they are very dark reddish brown, or 

 even piceous, and widening at points coalesce in a variety of 

 patterns ^^ and occasionally they entirely cover the elytra, leaving 

 the margin pale. The dark form, which is comparatively rare, 



1" See Horn's illustration, pL 7, fig. 20. 



