260 THE CHICAGO ACADEMY OF SCIENCES. 
Lymnea obrussa modicella BAKER, Bull. Ill. State Lab. N. H., VII, p. 103, 
1906.—HeENDERSON, Univ. Col. Studies, IV, p. 93, 179, fig. 35, 1907—DANIELS, 
Nautilus, XXII, p. 121, 1909. 
Lymnea humilis’ WHEATLEY, Cat. Sh. U S., Ed. 2, p. 23, 1845.—Lewis, 
Proc. Phil. Acad., 1856, p. 260.—Cooper, Amer. Nat., II, p. 486, 1868—WozrF, 
Amer. Journ. Conch., VI, p. 28, 1870.—Lerwis, Proc. Phil. Acad., 1872, p. 102; 
Proc. Phil. Acad., 1872, p. 109—RuoAns, Nautilus, XVIII, p. 66, 1904—BAxer, 
Nautilus, X VIII, p. 125, 1905; Amer. Nat., XX XIX, p. 673, 1905—Datt, Alaska 
Moll., p. 72, 1905 (part).—Pitspry and Ferriss, Proc. Phil. Acad., 1906, p. 161 (?). 
—Baker, Bull. Ill. State Lab. N. H., VII, p. 104, 1906—HENpbErRson, Univ. Colo. 
Studies, IV, pp. 93, 179, 1907.—StErKp, Proc. Ohio Acad. Sci., IV, p. 382, 1907.—- 
Jackson, Nautilus, XXI, p. 143, 1908—WaLKER, Ottawa Nat., XXII, p. 90, fig 
1, 1908.—LErmonp, Shells of Maine, p. 38, 1908 (part). 
Lymnea humilis DEKay, Cat. An. N. Y., p. 32, 1839.—Grrarp, Proc. Nat. 
Inst., I, No. 2, p. 81, 1856—LeEa, Exp. in Neb., II, pt. 3, p. 724, 1859.—RoBErTs, 
Rep. U. S. Geol. Surv. Wyoming, 1870, p. 468—Topp, Proc. Am. A. A. Sci. 
XXVIII, p. 235, 1878—WaLkerR and Coo.ipce, Nautilus, XXII, p. 32, 1908. 
Limnea humilis MicuHets, Bost. Journ. Nat. Hist., IV, p. 336, 1843.— 
Stimpson, Sh. N. Eng., p. 52, 1851—CuHIcKERING, List. Sh. Portland, Me., 1855 
or 1856.—Lewis, Proc. Bos. Soc. N. H., VI, p. 2, 1856—Hiccrns, Cat. Sh. Colum- 
bus, p. 6, 1858——BLanp and Cooper, Ann. N. Y. Lyc. N. H., VII, p. 370, 1862.— 
WHITEAVES, Can. Nat. & Geol. VIII, p. 103, 1863.—Cpr., Rep. Brit. Asso., 
1864, p. 630.—Husparp and SmitH, Ann. N. Y. Lyc. N. H., VIII, p. 152, 1867.— 
Tryon, Amer. Journ. Conch., III, p. 196, 1867—Axpricu, Rep. N. Y. State Col. 
N. H., XXII, p. 23, 1868.—CurriEr, Kent. Sci. Inst. Mis. Pub. No. 1, 1868.—. 
Dax, Proc. Bost. Soc. N. H., XIII, p. 248, 1870—SmitH and Prime, Ann. Lyc. 
N. H., IX, p. 402, 1870.—Cooprer, Proc. Cal. Acad. Sci., IV, p. 96, 1870—Gou Lp, 
Binney’s Ed. Inv. Mass., p. 482, 1870—Cpr., Smith. Mis. Coll., 1872, p. 116— 
JerFreys, Ann. Mag. N. H., ser. 4, X, p. 247, 1872.—Byrnes, L. & F.-W. Sh. 
Cin., p. 1, 1872—Tryon, Con. Hald. Mon., p. 105 (79), 1872 (part).—JEFFREYS, 
Journ. Conch., I, p. 16, 1874—-Smitu, Rep. U. S. Fish. Com., 1874, p. 702.— 
CALKINS, Proc. Ottawa Acad. Sci., 1874, p. 25; Cin. Quart. Journ. Sci., 1, p. 
323, 1874.—Yarrow, U. S. Geol. Surv. 100th Merid., V, p. 945, 1875.—Dawson, 
British N. A. Bound. Com., p. 349, 1875.——WALKER and BrEcHER, Proc. Ann. 
Arb. Sci. Asso., p. 45, 1876.—Pop. Sci. Mon., X, p. 248, 1876—Jones, Moll. of 
Nova Scotia, p. 10, 1877-——WaALKER, Journ. Conch., II, p. 330, 1879.—Grszons, 
Journ. Conch., II, p. 133, 1879—CxeEssin, Mal. Blatt., n. s. I, p. 27, 1879 (part). 
—STEIN, Ind. Dept. Stat. & Geol., 1880, p. 458—CaLL, Amer. Nat., XV, p. 586, 
1881.—Ciessin, Mal. Blatt., n. s. III, p. 81, 1881 (part)—Jorpan, Nova Acta 
Ksl.-Leop.-Carol Deutsch Akad. Natur., XLV, p. 367, 1883—Sampson, Bull. 
Sedalia N. H. Soc., No. 1, p. 24, 1885—Moore and Butter, Bull. Brookville 
Soc. N. H., No. 1, p. 43, 1885.—Curisty, Journ. Conch., IV, p. 347, 1885—WEsT., 
Vega Exped., IV, pp. 166, 220, 1885.—SterkI, Nach. Mal. Gesell., XVIII, p. 
19, 1886.—BrAuCHAMP, Sh. N. Y., p. 4, 1886—H. F. CarpeNTER, Random Notes, 
III, p. 86, 1886.—Marsu, Conch. Exch., II, p. 110, 1887—Sampson, Amer. Nat., 
1As there is no possible means of knowing just what these records of 
humilis were founded on, they are all assumed to refer to the northern form 
which is here called modicella: By this treatment all of the references are 
brought together. Several references from the south (Louisiana, Texas, New 
Mexico) may have been founded on the true humilis, but the author has not 
been able to verify them. 
