292 THE CHICAGO ACADEMY OF SCIENCES. 
Acella galbana Lewis, Bull. Buff. Soc. N. H., 1874, p. 135. 
Limnea trasku Martens, Mal. Blatt., XIX, p. 78, 1872. (?) 
SHELL: Small, subovate, rather inflated, thick; periostracum 
whitish or yellowish; surface shining, growth lines coarse, prominent, 
without spiral lines; whorls 5, convex, roundly shouldered, rapidly 
increasing in diameter , the body whorl very large and somewhat flat- 
tened on the periphery; nucleus small, flatly rounded, dark colored, 
similar in form to that of obrussa; spire usually short, broadly acutely 
conical, generally occupying about half the length of the shell; sutures 
rather deeply impressed; aperture ovate, generally rounded above and 
below ; outer lip simple, acute; inner lip erect, forming a rather broad, 
fat reflection over the umbilical region which emargins the umbilical 
chink and which is without plait-like thickening; there is a thin wash 
of callus on the parietal wall; umbilical chink narrowly open; speci- 
mens are frequently imperforate. 
Length. Breadth. Aperture length. Breadth. 
8.00 4.50 4.25 2.00 mill. Say’s type 
8.50 5.00 4.75 PLEXO) | Alpena, Mich. 
8.50 5.00 5.00 BIND i 
8.00 3.75 4.00 2.00 “ White Pond, N. J. 
7.00 3.70 3.00 Oma = i 
7.00 4.00 3u75 2.00 “ 4 Ss 
10.00 5.00 5.50 Dr se ene Squaw Island, N. Y. 
9.00 4.90 6.00 BON 9 is % 
8.50 4.90 5.00 250) a 
9.00 5.00 5.50 3.15 x 
7.50 4.50 4.75 2.50 
Tyree: Academy of Natural Sciences, Philadelphia, one specimen, 
No. 58821. 
Type Locauity: Marl pit near Franklin, New Jersey. 
ANIMAL, JAW, RADULA and GENITALIA: Unknown. 
RANGE (Figure 32): From New Brunswick and Anticosti Island 
west to Washington, Alaska south to southern Indiana and southern 
California. : 
Galbana is not found at present farther south than the Transition 
life zone, though. it ranges north well into the Boreal life zone. The 
marl deposits, however, show that in Post-Glacial Times it ranged 
south in Indiana (Upper Austral) and extended as far north as the 
Arctic circle. It is exceedingly abundant in the marl deposits of New 
Tersey, New York, Michigan and Indiana, and must have been at one 
time one of the commonest of the smaller Lymnzas. The wide gaps 
in its distribution show that much work is yet to be done before its 
