414 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 117 



their bicolored antennae. The male genitaha indicate a close re- 

 lationship with both P. ruficolle and P.flavipes. 



Numerous deviations in form have been encountered, making it 

 necessary to preface a number of statements in the composite de- 

 scription with the word "usually." All of these deviations were care- 

 fully considered and were found to belong to one rather variable 

 species. Several of the synonyms were based on extreme variants of 

 of the typical form ; indeed, it is surprising that it was described only 

 under five different names. Prominent among these variations is 

 the elongate form which approaches that of P.flavipes. The relative 

 convexity of the elytral intervals and the position of the apex of the 

 prosternal process fluctuate considerably, even among individuals of 

 a single population. The dorsal surface lustre is constant. Specimens 

 appearing slightly glossy reveal their true lustre when touched 

 lightly with a brush dipped in ether. 



P. ruficorne has entered the economic literatm^e under the common 

 name "red-horned grain beetle" (Back and Cotton, 1953). It has 

 been reported commonly from shelled corn in Missouri, Iowa, and 

 Illinois. From all indications the beetle is particularly attracted to 

 grain having a high moisture content which makes it damp and moldy; 

 it is doubtful that it ever attacks sound grain. Normally it is found 

 under the bark of dead trees and in fleshy fungi. On several oc- 

 casions it has been reported coming to hghts. 



Types. — Diaperis ruficornis Stm"m; not seen; type locality, "Amer. 

 bor." Platydema rufiventris Laporte and Brulle; not seen; type 

 locality, "Philadelphie." Neomida rufa Melsheimer ; not seen; 

 missing from Melsheimer collection (MCZ) (E. A. Chapin, in litt.); 

 type locality, Pennsylvania. Horn (1870) states that it is "but an im- 

 mature specimen of ruflcorne." Platydema analis Haldeman: MCZ 

 8369; bears a pink "Middle States" label. This is a very typical 

 specimen of ruficorne as defined herein. Both hindlegs and both 

 antennae are gone and the pin is badly corroded. Platydema opaculum 

 Casey: USNM 46813; bears a "Penn." label but said by Casey 

 to be from near Philadelphia. A year after its description, Horn 

 (1885) placed it mto synonymy with P. ruficorne, calling it var. 

 anale Haldeman. Casey himself (1890) somewhat reluctantly 

 concurred, with the comment that it "appears to be a small 

 and rather abnormal specimen of ruficornis Sturm ..." and 

 placed it under that name in his coUection. It falls well within the 

 range of variation, including size (3.9 mm. long), as described above. 

 Platydema pallens Laporte and Brulle (1831, p. 377) is sometimes 

 included (Gebien, 1911, 1940; Leng, 1920), as a synonym of the present 

 species. The original description could fit any number of species in- 

 cluding P. ruficorne. The measm-ements given (3 fines long, 2 lines 



