PROCEEDINGS OF THE XATTOXAL MUSEUM. 



To convey a correct impression of the g-eographical distribution of 

 the ])eetles, it is absolutely essential to obtain accurate lists of the 

 ('Oleoptera of the different sections of this country. The first step \n 

 this direction was taken by Messrs. E. A. Schwarz and H. G. Hu])baid, 

 who prepared the Coleoptera of Michigan and Florida, and their exam- 

 ple was followed by numerous other entomologists. Of special inter- 

 est for comparison is Dr. John Hamilton's Catalogue of the Coleop 

 tera of Southwestern Pennsylvania (1895). 



There are especially three localities in the immediate vicinity of 

 Washington which have been very carefully explored by the ento- 

 mologists: The meadows, rocks, and woods along both sides of the 

 Potomac and including the river flats across Long Bridge; the valleys 

 of the Rock Creek, and the banks of Eastern Branch. The richest 

 collecting ground near Washington has been the rocky ledges and 

 ravines along the south banks of the Potomac just above the Free 

 Bridge. The Rock Creek region is also full of interest. The creek 

 cutting its snake like course here through solid rocks, leaves deep 

 ravines and winds its way among mossy sand Imnks and swampj?^ 

 meadows, presenting a variet}' of conditions that always assures the 

 collector a rich harvest. In striking contrast to the above localities 

 arc the banks of the Eastern Branch, with their extensive marshes 

 of wild rice. Here a great many species were found not occurring 

 elsewhere in the District. 



Some representative forms of the austroriparian fauna arc found 

 all along the Atlantic coast from Florida to New Jersey, but the 

 majority do not extend more northerly than the Chesapeake region, 

 while certain northern species find their southern limit of distribution 

 in this vicinity. 



The following arc examples of austroriparian species which tind 

 here their northern limit: 



Oinopln'on lahlatam^ PlatynuH strlatopunctatu.s and jjictleoniix, 

 Aiiaf>'!cJi!s iithiuta^ Celina angustata, Bryaxis l}eJfra(/e/^ Lio rechmi^ 

 Mci'intlnis. scohhiuhi^ lschiod(mtu>i solcatus^ OzogtiatJnis jlorldanus, 

 (Ed/o)n/ch!s buligoptera^ Lactica tlbialif<, Mecynotai'><ii>< candidus^ 

 Xyloph'd ii>^ notatas^ Jlyporhagus punctulatus^ Liopus ctossuIus, Au- 

 Icutes tdcJiygouoldeK^ Ceutoi^hynelms sicvJux^ Ooinorphldlus Isevlcollis, 

 Ch»t()ca'h(s setoKus^ and others. 



Of Alleghenian forms, which tind here their southern limit, we have: 

 dcindela I'mjifronK^ LSla fui'sada^ Ipx confltioduK, Boras unlcol<>i\ 

 Ldt'tcohlus erichson/\ liJi/xoi^niiiis vtrldlxneux^ Ckirehai'a longida^ 

 Enchodes sericea, Pteroxftclntx corvlnus^ Platynus ohsoletus, Acalyptus 

 carpini, and others. 



The great bulk of our Coleoptera, however, belongs to the Caro- 

 linian fauna. 



