496 



MICHIGAN SURVEY, 1905. 



PUNCTUn PYQM/EUM (Draparnaud). 



Shell very minute, broadly umbilicated, subglobose; red- 

 dish horn-color, shining, finely striate and with microscopic 

 revolving hnes; whorls 4, convex, gradually increasing; ap- 

 Fig. 91. erture subcircular, oblique; peristome simple, acute. 



^•(5Ky.r- Alt. 1, greater diam. H mm. 

 Helix pygmcea, Draparnaud, Tabl. Moll. France, 93, (1801). 



Microphysa , W. G. Binney, Man. Am. Land Shells, 71, fig. 31, 



(1885). 

 Punctum pygmcBum minutissimum, Walker, Rev. Moll. Fauna Mich., 16, 



(1894). 

 Generally distributed, but rarely found on account of its minute size. 



Genus SPHYRADIUH Charpentier. 

 Shell elevated, pupaeform. Jaw and radula as in Punctum. 



pp5pvj ,C^ 



[ I 



rl R R 



Fig. 92. Dontition of S. edentulum. (Gwatkin.) 



Fig. 93. 

 S. edentulum. 

 X11.6. (Binney.) 



Pupa edentula 

 Vertigo simplex 



SPHYRADIUM EDENTULUM (Draparnaud). 



Shell minute, cylindrical, apex obtuse, finely and obliquely 

 striate, light horn-color; whorls 5, moderately convex, suture 

 deep; aperture circular; the peristome nearly continuous, simple, 

 everted at its columellar margin, where it partially conceals a 

 small umbiUcus; aperture edentulous. 



Alt. 1 3-5, diam. 4-5 mm. 



Draparnaud, Hist. Moll., 52, pi. III., fig. 28-9, (1805). 



W. G. Binney, Man. Am. Land Shells, 191, fig. 195, (1885). 



, Miles, Rep. Geol. Surv. Mich., 236, (1861). 



, Currier, Shell-bearing Moll. Mich., 5, (1868). 



, DeCamp, Shell-bearing Moll. Mich., 7, (1881). 



Pupa edentula simplex, Walker, Rev. Moll. Fauna Mich., 17, (1894). 



Apparently of general distribution, though not abundant. Characterized 

 by its cylindrical form, striate surface and edentulous aperture. 



Family PHILOnVCID/E. 



Animal limaciform, mantle covering the whole body; jaw with or without 

 anterior ribs and a median projection to cutting edge; lingual membrane of 

 Helicidce; no shell. 



KEY TO GENERA OF PHILOMYCID^. 



I. Jaw smooth Philomycus. 



II. Jaw ribbed Pallifera. 



