i a a Cae | ahd cedars i — \ 
THE NATURAL HISTORY SURVEY. 159 
Animal: Blackish above and on head and eye-peduncles, 
yellowish-white on base and foot; foot long and narrow, 32 
mill. long and 4 mill. wide (1I1g10); eye-peduncles long and 
slender, tapering; heart situated on direct line drawn trom the 
umbilicus to the upper termination of the peristome, beats 
eighty-eight per minute regular. 
Jaw. Similar to that of siyrotdes, with ten ribs. | 
Radula formula: ?2+12+4-4+13+% (43—1—43); similar 
to that of P. thyroides, but without side cusps on any of the 
teeth. 
Genitalia: ‘The penis sac isthe conspicuous feature of the 
system; it is longer than the oviduct and almost as stout, of 
about equal size throughout; it has the entrance of the vas 
deferensand the retractor muscle at its bluntapex. The geni- 
tal bladder is small, lengthened oval, with a long, slender duct. 
The prostate is narrow, stout, prominent, cord-like. The vas 
deferens is large. The other organs present no peculiar fea- 
tures.” (W. G. Binney.) 
Distribution: Western Pennsylvania to Minnesota, south 
to Wyandotte, Kan., Jackson County, Alabama, and Sea Is- 
lands of Georgia. (Pilsbry.) 
Geological distribution: Pleistocene; Loess. 
Habitat: Found in moist woods under logs and débris of 
all kinds. 
Remarks: Unless care is taken this species will be con- 
founded with small forms of “#yvoides. Indeed, it has much 
the aspect of the form known as ducculenta. The aperture in 
clausa is always larger (in comparison to its size) and rounder 
than in ¢hyroides, and the shell is always more globose and there 
is never a tooth on the parietal wall. The animal is very rapid 
in movement, is most inquisitive, and very readily crawls over 
the hand. It is amost uniform species, showing almost no va- 
riation. The specimens from Joliet are unusually large and 
fine. The species is not very common, except in the region 
around Joliet, and it is confined to the southern and western 
regions, 
59. Polygyra pennsylvanica Green, pl. xxix, fig. 3. 
Helix Pennsylvanica GREEN, Contr. to Macl. Lyc., Nos. 1, 8, 1827. 
Shell: Obtusely conical, elevated, imperforate; surface 
sculpture as in c/ausa; color light yellowish, straw or dark horn; 
nuclear whorls smooth; periphery rounded; sutures well im- 
