234 



B. SHIMEK 



as occurring in Hickman County, Ky. 1 This is probably H. orbicu- 

 lata, as Dana reports this species from Hickman, Ky., on the authority 

 of Wetherby, 2 though Hickman County is so near the southern limit 

 of fossil H. occulta that it may have been the latter species. How- 

 ever, neither conclusion would affect the discussion herein presented. 

 • Since these two species have been frequently confused, the error 

 leading to erroneous references to distribution which would mislead 

 those who are not familiar with the facts in the case, some additional 

 notes on this point are here offered. 



Binney's and Aughey's errors have been noted in the previous 

 paper. 3 In 1868 Tryon repeated Binney's error, 4 stating that H. 

 occulta is found "fossil and bleached in the post-Tertiary of the west- 

 ern states, Indiana, Ohio, Mississippi, etc." All the authentic records 

 of Helicina from Mississippi are those of H. orbiculata. Dr. A. 

 Binney reported that species from the loess of Natchez in 1846. 5 In 

 1854 Wailes reported "Helix helicina'''' from Mississippi, this evi- 

 dently being intended for H. orbiculata. The writer found it very 

 common in the loess of Natchez in 1898, 6 but did not find H. occulta. 

 It is safe to say that all specimens of fossil Helicina reported from 

 south of Kentucky are H. orbiculata, fossils of that species being 

 known only from the loess bluffs along the Mississippi River from 

 Mississippi to Kentucky. Recent specimens of the species may be 

 found from southern Florida to Texas, and northward to Tennessee, 

 and Jasper County, Mo., the latter being the most northerly locality 

 known. 7 



Other errors have resulted from this confusion of species. Thus, 

 in 1875, Cox stated 8 that Helicina occulta Say, "has not, I believe, 

 been found living north of Arkansas." The statement applied, at 

 the time, only to H. orbiculata. Dr. Snyder's report of H. orbiculata 9 



1 D. D. Owen, Geological Survey of Kentucky (1856), p. 18. 



2 Manual of Geology, 4th ed. (1895), p. 966. 



3 Loc. cit., p. 176. 



4 American Journal of Conchology, Vol. IV, p. 12. 



s Proceedings of the Boston Society of Natural History, Vol. II, p. 130. 



6 See American Geologist, Vol. XXX, pp. 279-98. 



7 See Nautilus, Vol. VIII (1894), p. 18. 



8 Geological Survey of Illinois, Vol. VI (1875), p. 210. 



9 In Leverett, The Illinois Glacial Lobe, Monograph No. XXXVIII, U. S. Geol- 

 ogical Survey (1899), p. 171. 



