LYMNZIDZ OF NORTH AMERICA. 193 
Acella gracilis Tryon, Amer. Journ. Conch., I, p. 257, 1865.—CURRIER, 
Amer. Journ. Conch., I, p. 294, 1865—Datt, Ann. Lyc. Nat. Hist., IX, pp. 340, 
349, 1870.—Lewis, Bull. Buf. Soc. N. H., HH, p. 135, 1874.—DercampP, Kent Sci. 
Inst. Pub. No. 5, 1881—GrantT, Rep. Nat. Hist. Surv. Minn., XVI, p. 483, 
1888.—CuHENu, Man: de Conch., II, p. 480, fig. 3545. 
Limnea haldemani DesHayes, BINNEY, Journ. de Conch. VII, No. 4, 
Oct., 1867—-Tryon, Con. Hald. Mon., p. 114 (88), 1872—Baker, Bull. Ills. 
State Lab. N. H., VII, p. 103, 1906——Sterx1, Proc. Ohio State Acade Sci LVE 
p. 382, 1907. 
Limnea jayi DUNKER, WaLkER, Nautilus, XXII, p. 18, 1908. 
SHELL: Very slender, thin and fragile; color of periostracum 
yellowish-white ; surface generally dull, growth lines closely set, fine ; 
no spiral sculpture; nucleus consisting of about one whorl which is 
long-oval in outline and resembles the end of a bullet; when turned 
to one side the outline of the nuclear and first post-nuclear whorls re- 
sembles a liberty cap (pl. XLIX, fig. E); whorls 5%, very oblique 
and flat-sided; spire very slender and acute, much longer than the 
aperture; sutures heavily impressed, bordered by a narrow band indi- 
cating the position of the previous connected lips ; aperture long-ovate, 
elongated and narrowed, made continuous by the heavy and raised 
inner lip; peristome thin, acute, inner lip elevated in some specimens 
and causing the aperture to be continuous; in other individuals it is 
attached but not appressed to the parietal wall; the aperture is also 
twisted to the left and narrowed at its junction with the body whorl; 
axis gyrate; there is a small umbilical chink; there is no plait on the 
columella, which is almost straight. 
Length. Breadth. Aperture length. Breadth. 
18.50 3.50 
€ 
~ 
25 2.25 mill. 
20.00 3.75 8.00 Dirge 
19.00 4.00 7.50 250) = 
25.00 5.00 10.50 3.00 “ 
24.00 5.00 10.00 3:00) 
Types: Not in Jay collection (vide letter from Mr. L. P. Grata- 
cap, Amer. Mus. Nat. Hist.). 
Type Locatity: Lake Champlain. 
AnimAL: Yellowish, flecked with fine white dots, which become 
larger on sides of body and edge of mantle; under side of foot bor- 
dered by a dark margin; tentacles small; foot broadly long-ovate and 
shorter than aperture, one specimen measuring as follows: shell, 22.50 
mill., aperture 11.00 mill., foot 7.00 mill.; the shell and animal are in 
life almost transparent, the organs showing plainly through the shell, 
especially those of the digestive system. 
