108 Bulletin 1, Biological Society of Washington, 1918. 



Great Falls is distinguished zoologically as well as botani- 

 cally, for as previously mentioned, the Falls is the upstream 

 limit of 3 species of anadromous fishes, and the only credible 

 record, and that an ancient one, for the rattlesnake, is for 

 Great Falls. So far as insects are concerned, this vicinity 

 is an excellent collecting place. It is an especially good 

 locality for the following scarce robber flies: Lasiopogon 

 tetragrammica, Nicocles pictus, Nusa fulvicauda, Lampria 

 bicolor, and Asilus maneei. The deer fly, Chrysops dim- 

 mocki, has been collected only at Great Falls in our region ; 

 and the same is true of the leptids, Rachicerus obscuripennis 

 and R. nitida, and the syrphids, Microdon anrulentus and 

 Pelecocera pergandei. Among Hemiptera the small cicada, 

 Tettigia hieroglyjrfiica, and the scutellerid, Acantholoma 

 denticulata, have been collected solely near Great Falls, and 

 among beetles the clerid, Pyticera quadripunctata. The ear- 

 wig, Doru aculeatum, has been taken exclusively in a small 

 swamp on the Virginia shore here, and the large velvet ant, 

 Dasymutilla occidentalis, has been observed more plenti- 

 fully along the towpath on the Maryland shore than else- 

 where. 



In conclusion let it be understood that the collecting 

 localities treated in the foregoing paragraphs, even if added 

 to those described by Ward and Coues, do not exhaust the 

 list of favorable collecting places in the Washington region. 

 Most interesting spots undoubtedly yet await exploration. 

 Other things being reasonably equal, the amount of good 

 collecting done determines the rank and relative interest of 

 the various localities. The many good things discovered on 

 Plummer's Island, for instance, were brought to light by the 

 most intensive collecting that has been done on any area 

 of equal extent in our region. The rewards for collecting in 

 any even partly unspoiled neighborhood seem to be in pro- 

 portion to the efforts put forth. May our entire area be 

 made to yield the maximum of species, facts and interesting 

 experiences, but may none of it be ravished of its natural 

 charms. 



