324 THE CHICAGO ACADEMY OF SCIENCES. 
Limnea palustris michiganensis WALKER, Nautilus, VI, p. 33, pl. 1, figs. 
9, 10, 1892; Rev. Moll. Mich., pp. 7, 18, 1894—-BaKer, Trans. Acad. Sci. St. 
Louis, XL, p. 17, 1901 (part); Moll. Chi. Area, II, p. 276, pl. 31, fig. 25, 1902 
(part) —DaAnIELs, Rep. Dept. Geol. Nat. Res. Ind., p. 636, 1902.—BiatcH. & 
DANIELS, Rep. Dept. Geol. Nat. Res. Ind., XX VII, p. 596, pl. 1, fig. 12, 1902. 
Limnophysa palustris michiganensis BAKER, Journ. Cin. Soc. N. H., XIX, 
p. 84, 1897. 
Limnea palustris var. michiganensis CHADWICK, Bull. Wis. Nat. Hist. Soc., 
IV, p. 81, 1906; Nautilus, XX, p. 22, 1906. 
Lymnea palustris michiganensis BAKER, Bull. Ill. State Lab. N. H., VII, 
p. 105, 1906. 
SHELL: Elongated, narrow, attenuated, rather thin; periostracum 
light yellowish horn, frequently jet black; occasionally longitudinally 
striped; surface dull to shining; sculpture as in palustris; whorls 
6 to 7, rather evenly increasing in size, typically flatly rounded, espe- 
cially the body whorl; spire long and very much attenuated; sutures 
usually less impressed than in palustris; aperture elongate-ovate, gen- 
erally much shorter than the spire; peristome with heavy varical thick- 
ening; inner lip narrow, reflected and appressed to the columellar 
region, forming a distinct plait and usually completely closing the 
umbilicus ; parietal callus rather wide, heavy. 
Length. Breadth. Aperturelength. Breadth. 
30.00 12.00 13.00 5.00 mill. Type umbrosa 
32.00 12.00 14.00 650) “  elodes 
31.00 10.50 12.00 6.00 “ White Co., Ind. 
30.00 11.00 12.00 6.00) = cs - 
30.00 10.50 11.50 550) a 4 
30.00 11.00 12.50 62580 = ‘ 
26.00 9.50 11.50 550) = = is 
21.00 8.50 11.00 41500 a ef 
28.25 9.00 11.90 5:50 “~ Leekport- it: 
28.00 9.00 11.00 POON ‘ mS 
37.00 14.00 16.00 8.00 “ Lake Mendota, Wis. 
Types: Academy of Natural Sciences, Philadelphia; elodes, one 
specimen, No. 58638; wmbrosa, two specimens, No. 58504; michigan- 
ensis, Walker, coll. Bryant Walker; cotypes, Acad. Nat. Sci. Phil., 
No. 58690. 
Type Locatity: Canandaigua Lake, New York, for elodes; 
waters of the Missouri, near Council Bluffs, Iowa, for wmbrosa; Ecorse 
and Greenfield, Wayne County, Michigan, for michiganensis. 
ANIMAL: Not differing externally from palustris. 
JAw, RaAputa and GENITALIA: Not differing essentially from 
palustris. 
RANGE (Figure 35): Connecticut to South Dakota; Rainy Lake, 
Ontario, south to northern Kansas and southern Ohio. 
