148 Richard L. Hoffman 



slightly posterior to the posititions shown in my drawing. 



In most other respects, this species is extremely similar in body 

 form and minute details of structure to B. lacunarium, which was also 

 named by Zimmermann at the same time as plagiatum. Aside from the 

 setae just noted, the obvious external difference evident to me is the 

 apical yellow elytral spot, which appears to be the result of local trans- 

 lucence of the integument that allows the folded wing tips to show 

 through, and not the reflection of yellow pigment per se. 



Contrary to Lindroth's remark that "It is difficult to understand 

 how this species could be regarded as a synonym (spotted form) of 

 lacunarium ..." I can see every justification for postulating a close rela- 

 tionship. Lindroth placed plagiatum in his striola group, so far as I can 

 perceive, solely on the basis of elytral spots, against the more solid evi- 

 dence of both body form and penial structure. His own drawings (Figs. 

 155f, 159f) show that the internal armature of the penis sac allies plagia- 

 tum with lacunarium at the same time it shows these two species to be 

 disjunct in the groups to which he assigned them. Perhaps both, along 

 with B. texanum, merit recognition in a separate species group. 



Several seasons of fairly intensive field work in southwestern Virgin- 

 ia have failed to disclose plagiatum in the mountains, where it seems to 

 be replaced by lacunarium. The collective localities now known suggest 

 a wide distribution at low to moderate elevations, extending from New 

 Jersey south to North Carolina, east of the Blue Ridge, and then, pre- 

 sumably, northward on the west side of the Appalachians as far as Lake 

 Ontario. The map (Fig. 2) graphically represents this apparent "Upper 

 Austral" distribution. 



ACKNOWLEDGMENTS.— C. S. Brimley's material of Bembidion 

 was kindly loaned by Mr. James E. Greene, N. C. Department of Agri- 

 culture, Raleigh; Dr. Alfred F. Newton, Jr., Museum of Comparative 

 Zoology, examined the type specimen of plagiatum for me and also 

 identified the staphylinids taken at Cobb's Branch; Dr. Thomas C. Barr, 

 Jr., University of Kentucky, and Dr. Terry L. Erwin, National Museum 

 of Natural History, generously permitted me to report unpublished 

 information from their files. Mr. Robert Davidson, Carnegie Museum, 

 read an early draft of the manuscript and provided information about 

 the location of "Allegheny, Pa.". Roberta R. Hoffman provided diligent 

 and skillful assistance on collecting trips. I am very much indebted to all 

 of these persons for their contributions to the knowledge of an interest- 

 ing and generally overlooked ground beetle. 



