38 PROCEEDINGS OP THE NATIONAX. MUSEUM vol.70 



Distribution. — Massachusetts, New York, Pennsylvania, New Jer- 

 sey, Ohio, Illinois, Michigan, Missouri, Maryland, District of 

 Columbia, Virginia, North Carolina, Alabama, and Tennessee. 



Oedionychis circuindata has been one of the most confused of the 

 North American species of Oedionychis. In most collections it 

 has been labeled Oe. quercata Fabricius. Examination of the old 

 Bosc collection at Paris shows that the original Oe. quercata has 

 lounded elytra, and elytral margins varying from reddish (Fa- 

 bricius' ferrugineus) to piceous (see description of Oe. quercata). 

 Randall's brief description of his Oe. circumdata appears to be the 

 earliest recognition of this wide-spread species. He described it as 

 having the head somewhat black, the thorax testaceous and elytra 

 black, densely punctured, with a testaceous margin. It was collected 

 in the vicinity of Boston. Nine years later Melsheimer described a 

 species from Pennsylvania, closely allied to quercata, as Oedionyclm 

 liinhalis. The Melsheimer type at the Museum of Comparative 

 Zoology has the pronotum rather obscurely yellowish brown, which 

 is undoubtedly the result of discoloration and not a specific char- 

 acter. Crotch in 1873 placed limbalis as a synonym of quercata. 

 Horn in 1889 added a finishing touch of confusion by describing a 

 variety of Oe. limbalis, var. subvittata, and also by putting the Fa- 

 brician species, Oe. obsidiana, as a variety of Oe. quercata. Exami- 

 nation of the Horn collection shows that what Horn described as 

 Oe. limbalis, together with his variety subvittata, is a distinct species 

 and not at all the limbalis of Melsheimer (see Oe. subvittata). 



Oe. circumdata differs from Horn's dark form of limbalis in 

 shape. Horn lays much stress on the fact that limbalis is the most 

 " broadly oval species in our fauna," whereas Oe. circumdata tends 

 to have quadrate elytra, especially in the male. In Horn's collec- 

 tion are no specimens with so darkly piceous elytra as the original 

 Melsheimer limbalis. Horn's specimens are plainly the darker, 

 usually reddish brown form of his variety subvittata. The puncta- 

 tion in the main is sparser and coarser than in circuindata. I have 

 not seen any specimens of Oe. circumdata from north of Massa- 

 chusetts, whereas Horn's limbalis {subvittata) occurs as far north 

 as Quebec. 



The beetle described by Horn as a form of Oe. quercata with 

 yellow thorax is really Randall's Oe. circumdata. But he has con- 

 fused under the form having a dark thorax the Fabrician species 

 Oe. obsidiana which bears only a superficial resemblance to Oe. 

 circumdata. In circwmdata the prothorax is never piceous and the 

 eyes are small and widely set, the interocular space being fully one- 

 half the width of the head, whereas in obsidiana the prothorax is 

 more or less piceous and the eyes are large, the interocular space 



