Sa POLYGYRA PROFUNDA ALBA (Walker). 
Pale horn color without bands. This variety occurs occa- 
sionally in Washtenaw and Monroe counties, associated with 
the typical form. The other extreme (wzzco/or) in which the 
bands coalesce and cover the entire surface has not yet been 
noticed in this state. 
9, PoLyGYRA SAYII (Binn.) 
Rare and restricted to the northern part of the state. 
Reported from Charlevoix, Presque Isle, Huron and Tuscola 
counties. 
10.° PoLyGyRA ALBOLABRIS (Say). 
Abundant over the entire state, and exhibits considerable 
variation in size, color and thickness of the shell. Streng 
states that ‘‘it was formerly abundant in Kent county, but is 
becoming scarcer.” The variety cited by DeCamp as rufa 
DekKay does not differ sufficiently in color to justify its reten- 
tion even as a color form. 
10a. POLYGYRA ALBOLABRIS DENTATA (Tryon). 
Occurs not infrequently associated with the typical form 
“Rate 1 Went county. otrenop 
Currier catalogued this form in 1868, and credited it to 
Say, and in my former lists I followed his citation, but Say 
does not appear to ever have described it. Pilsbry in his 
recent catalogue of the land shells of North America credits 
it to me. ‘This is erroneous as the variety was formally des- 
cribed by Tryon in the Manual of Conchology (III p. 150). 
10b. PoLYGYRA ALBOLABRIS MARITIMA Pils. 
The shells from Traverse City called ¢raversensis by 
Leach, which have been referred to this form, are not quite 
typical. T‘hey seem to be intermediate between the true 
maritima and the small form described by Sterki as var. 
minor. ‘The same form has been collected at Grand Rapids 
by DeCamp. Streng considers the Grand Rapids form identi- 
cal with mzzor and reports it as ‘‘scarce.”” The shell from 
Presque Isle county doubtfully referred to this form in the 
Nautilus (VI, p. 17) should rather be considered as mcnor. 
10c. PoLyGyrA ALBOLABRIS MINOR Sterki. 
This ‘‘ peculiar, small, thin-shelled form” differs from 
the usual form of a/bo/abris not only in these particulars, but 
in its very decidedly depressed form. The shell usually is 
noticably thinner than in the typical a/bolabris and with a 
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