1885.] PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 267 



No. 2 is the form figured by Biuuey as Fohjgyra cereolvs, large, high, 

 with stroug upper sculpture, broad lip, the base with the last three 

 whorls obvious, the internal lamina strong. It was called laminifera 

 b}' Binney in 1858. The type of Miihlfeld was like the ordinary small 

 Georgian form about 8.5'"'" in diameter. Inhabits East Florida and the 

 Keys. Hemphill states that at Long Key these inhabit low moist 

 ground covered with tall grass, so near the sea that unusually high tides 

 sometimes kill them by thousands. 



'No. 3. This is the small common form with comparatively delicate 

 upper sculpture, rather flat, horny looking, very smooth below, the lip 

 narrow and delicate, the mouth small; the last two whorls most obvi- 

 ous below. It is ofteu a little gibbous, and in most cases has a delicate 

 internal lamina. It is carpenteriana Bland in part; microdonia Des- 

 haj'es ; delitescens Shuttleworth ; and is very generally labelled volvoxis 

 Parrey ss. It is the form found at Bermuda and the Bahamas, is common 

 on the Florida Keys, and reaches to the westward as H. Febigeri Bland. 



Xo. 4. This is like the last but stronger, more shelly looking, coarser 

 in sculpture, proportionally larger every way, and is the most common 

 and widely distributed continental variety. It j)robably develops into 

 'No. 2 in favorable situations. 



There are many intermediate stages between all these forms. The 

 careful study which shall reveal the true relations of each to the other 

 is only possible for a resident in the region itself. No more interesting 

 and valuable contribution to our knowledge could be made than this. 

 One such study, if it were only thorough and careful enough, and em- 

 braced a sufiBcient range of habitat, would be a Rosetta stone, affording 

 a key to interpret the mysteries of many others. Shall not the South 

 afford us a couchological Champollion ? As for the subgeneric names 

 used in this connection it is quite evident to every one who surveys the 

 situation in the light of the changes made by authors from time to time, 

 that such names as PoJyrjyra, Dfvdalochcila, &c., are merely of sectional 

 importance. Thej' have a certain convenience in the literature, but cor- 

 respond more to a general facies than to any clearly definable charac- 

 ters. This, of course, does not apply to groups formerly included in 

 the genus Helix but now shown to differ structurally, such as Zonites, 

 Stenojms^ Nanina, &c. The distinctions, except in general facies, be- 

 tween Mesodon, Triodo2)sis, Stenotrejna, Bcedalocheila, Fohjgyra., &c., are 

 impossible to formulate and do not exist in nature any more than dis- 

 tinctions between individual waves of the sea, which, nevertheless, are 

 visible to all beholders. When these facts are fully recognized, a great 

 step toward a scientific comprehension of genera and species will have 

 been gained. 



Helix (Polygyra) pustula F<Srussac. 



Helix piistula F6t., Hist., p. 50, pi. 1, fig. 1. Biuney, 1. c, p. 286. (Polygyra.) 

 Habitat. — South Carolina, Georgia, Florida to Texas, Binney ; Cedar 

 Keys, Stearns and Hemphill ; Tampa City, Bland. 



