438 THE CHICAGO ACADEMY OF SCIENCES. 
forms, besides occupying a wholly different drainage area. It is one 
of the handsomest of the American Lymneas. 
Galba oronensis (Baker). Plate XLVII, figures 1-9. 
Limnea emarginata BAKER, Bull. Chi. Acad. Sci., II, pl. I, fig. B, 1900.— 
NyLaAnpeErR, Nautilus, XII, p. 104, 1900 (part); Distr., Lim. emarginata, p. 4, 
1901 (part). 
Lymnea decollata LERMOND, Shells of Maine, p. 38, 1908 (part). 
Radix decollata HEron, Ottawa Nat., I, p. 39, 1880. 
Lymnea decollata oronoensis BAKER, Nautilus, XVIII, p. 62, Oct., 1904.— 
LerMoND, Shells of Maine, p. 38, 1908. 
SHELL: Globose, inflated, solid; periostracum rich greenish horn 
or dark olivaceous, inclining to black in some specimens ; surface shin- 
ing, the growth lines somewhat elevated, sometimes producing indis- 
tinct, fine elevations; spiral sculpture of fine impressed lines, giving 
the surface a wavy appearance; nuclear whorls rounded, smooth, very 
dark horn colored, in outline resembling those of emarginata; whorls 
4% to 5; very convex, the body whorl almost globular, sometimes a 
little shouldered near the suture; spire broadly conic, depressed in 
some specimens; sutures impressed; aperture roundly ovate, produced 
anteriorly, occupying about two-thirds the length of the shell; it 
is somewhat narrowed at the posterior end; peristome thin and sharp; 
in old specimens the outer lip thickens within and forms a distinct 
varix; inner lip tightly appressed to the parietal wall where it forms 
a spreading callus; the umbilicus is either completely closed or (rarely) 
there is a very narrow chink; axis strongly twisted, forming a distinct, 
ascending plait; the interior of the aperture is brownish-red. 
Length. Breadth. Aperture length. Breadth. 
18.00 12.00 12.00 8.00 mill. Type. 
17.00 11.50 11.00 00) ra fe 
16.00 10.00 10.00 6.00 “ a 
12.00 9.00 8.75 a) * 
19.50 12.50 11.75 6.00 “ Caribou, Maine. 
20.00 12.50 13.00 TAO) 9 2 x 
18.00 10.00 10.00 GLOOM: x a 
Types: Collection, Bryant Walker, twelve specimens, No. 7912; 
cotype, Chicago Academy of Sciences, one specimen, No. 23784. 
Type Locarity: Orono, Penobscot Co., Maine. 
Raputa: Formula: #%+ 557484448455; 12 , (36-1-36) ; the 
teeth are similar in shape to those of catascopium and emarginata, dif- 
fering principally in the number of laterals, which are nine in the 
former and ten in the latter, while they number but eight in oronensis. 
The large number of transition teeth (six) in oronensis is noteworthy, 
there being but two in emarginata and four in catascopium. Laterals 

