LYMN-EIDZ OF NORTH AMERICA. 291 
RECORDS. 
UNITED STATES. 
MARL DEPOSITS. 
Itt1no1s: Chicago, Clyde Avenue, near Austin Avenue, six feet beneath 
surface, Cook Co. (Scharf). 
Marne: Barren Brook, Caribou, Aroostook Co. (Nylander). 
MicuicaAn: Pickerell Lake, Newaygo Co.; Marsh north side of Cedar 
Lake, Cedar Lake Station, Montcalm Co. (Walker). 
Wisconsin: Milwaukee, Milwaukee Co. (Baker; Slocum). 
OTHER POST-GLACIAL DEPOSITS. 
MicuicAn: Celery Swamp, Ann Arbor, Washtenaw Co. (Walker). 
New York: West Chartton, Saratoga Co., in extinct lake, under six feet 
of muck (H. B. McWilliams). 
Ecotocy: The habitat of decampi is probably the same as that 
of obrussa. 
REMARKS: Decampi is a very distinct and characteristic variety 
of obrussa, known at once by its strongly shouldered whorls and the 
peculiar manner in which the outer lip is arched at its junction with 
the body whorl. It appears to be one of the most common of the 
Pleistocene species and no doubt lived, with galbana, in the more or 
less icy waters of Post-Glacial Times. Small specimens may be con- 
fused with galbana, but that species does not have the elongate aper- 
ture nor the distinctly shouldered whorls of decampi, the aperture being 
rounder and the shell much heavier and more robust in galbana. De- 
campi varies greatly in the comparative height of the spire; examples 
from the same locality will embrace individuals with a long, slender 
spire and with a short, dome-shaped spire. The aperture also varies 
somewhat. The figures on plate XXXII illustrate this variation. 
Galba galbana (Say). Plate XXXII, figures 23-36. 
Lymneus galbanus Say, Journ. Phil. Acad., V, p. 123, 1825; Binney’s Ed., 
p. 114, 1858. 
Lymnea galbana Goutp, Lamarck’s Genera, p. 69, 1833—BAkKeErR, Trans. 
St. Louis Acad., XVI, p. 13, 1906 —WatKER, Rep. Geol. Surv. Mich., 1905, p. 465, 
1906. 
Limneus galbanus Letpy, Proc. Phil. Acad., I],*p. 281, 1845. 
Limnea galbana HALDEMAN, Mon. Limn., p. 51, pl. 13, figs. 22, 23, 1842. 
Limnea galbanus D’UrBAN, Geo. Surv. Can., Rep. Prog., p. 242, 1859— 
WHITEAVES, Can. Nat. & Geol., VIII, p. 103, 1863. 
Limnea galbana Binney, Check List, p. 12, 1860; Land & F. W. Sh. N. A., 
II, p. 72, fig. 117, 1865.—Currier, Kent. Sci. Inst., Mis. Pub., No. 1, 1868.— 
Sows., Conch. Icon., XVIII, Lim. sp. 107, pl. 15, fig. 107, a, b, 1872—CLEssIN, 
Mal. Blatt., n. s., III, p. 82, 1881—Watker, Nautilus, VI, p. 34, 1892; Rev. Moll. 
Mich., 1894, p. 18—Taytor, Ottawa Nat., VIII, p. 147, 1895—Amz1., Ottawa 
Nat., XI, p. 26, 1897——Baxer, Nautilus, XVII, p. 39, 1903—WuurteAves, Rep. 
Geol. Surv. Can., p. 163, 1905. 

