46 David L. Penrose, David R. Lenat, K. W. Eagleson 



Nais behningi R - - 



N. elinguis R R R 



N. simplex R R - 



Pristina idrensis R - R 



P. longiseta (?) R 



Specaria josinae R - - 



CRUSTACEA 



Lirceus sp. R 



Crangonyx sp. R 



Cambarus spp. C R - 



MOLLUSCA 



Goniobasis sp. A C 



Gyraulus sp. R 



Ferrissia sp. C A C 



Sphaerium sp. R R 



Pisidium sp. - - R 



"OTHER" 



Nematoda - R - 



Hydracarina R R - 



Dugesia tigrina R - - 



Cura foremanii R - R 



Prostoma graecens - R C 



(Iron) and Stenonema ithaca; Promoresia elegans and P. tardella; Mic- 

 rasema wataga and Brachycentrus; and Prosimulium mixtum and Simu- 

 lium spp.. 



Spatial Patterns. — Table 8 shows the number of taxa (by group) 

 with a preference for each area of the river basin. Data are not tabu- 

 lated for unusual taxa. Within this group, 86 taxa (64%) showed some 

 spatial preference. 



Longitudinal zonation along lotic systems has been demonstrated 

 many times in rivers throughout the world, and Hynes (1972) listed over 

 100 examples. Our intent here is simply to illustrate the expected pat- 

 tern in a small southeastern river. 



Comments on Particular Taxa. — The French Broad River data set 

 contained many unusual collection records, especially for Ephemero- 

 ptera and Chironomidae. An extremely high diversity was found within 

 the genus Ephemerella (24 species). These species often had a slight 

 degree of spatial and temporal overlap; single river stations in the spring 

 of 1979 had up to 20 species of Ephemerella. 



The "new genus near Centroptilum" is a highly unusual mayfly, 

 characterized by long gills on the fore coxae. The morphology of this 

 species will be described by Carlson and Lenat (in prep.). Brachycercus 

 nitidis is infrequently collected in routine stream collections (Berner 

 1977). We found this species only in samples taken near the river bank. 

 Baetisca berneri was recently described from West Virginia by Tarter 



