56 THE NAUTILUS. 
I may add that the 8. bettii var. brevior of Smith, is in my opinion 
distinct from S. bettii and should be raised as S. brevoir to specific 
rank. I have examined a large number of both forms. S. bettii is 
a species of the wooded zone, S. brevior of the dry zone. It is prob- 
able that S. wolfi Reibisch may be only a variety of S. bettir. 
The final report on Dr. Baur’s collections will not long be delayed. 
The species will be figured and their anatomical characters dis- 
cussed. The most important fact thus far determined is the close 
alliance of all the Nesiotes, Rhaphiellus and Pleuropyrgus to the 
American Bulimuli of the type of B. serperastrus. The different 
forms of the shell are dynamic not genetic differences, and there is 
no doubt as to the exclusively American type of the whole fauna, 
when the groups represented are not of world wide distribution. 
PRELIMINARY NOTE ON THE SPECIES OF STROBILOPS.! 
BY H. A. PILSBRY. 
The United States species of this genus have generally been 
believed to be but two in number, the “ Helix” labyrinthica of Say, 
and Hubbardi of A. D. Brown; the types of both being in the 
museum of the Academy of Natural Sciences of Philadelphia. 
The writer some months ago, gave the varietal name virgo to 
specimens sent him for determination by Rev. H. W. Winkley,’ and 
later the name affinis* to another form. 
Recently, with the assistance of Mr. H. E. Sargent, the various 
species and varieties have been re-examined and compared, with the 
result of finding that, in what has hitherto passed as “ H. labyrin- 
thica,” there seem to be at least three well marked species. These 
species agree in general form and sculpturing, but differ in size, 
color, degree of depression, and especially in the internal lamelle of 
1 Strobilops Pilsbry, Proc. Acad. Nat. Sci. Phila., 1892, p. 408, S¢robila Morse 
1866, not S¢vodz/a Sars, 1883, nor Stvobz/us Anton, 18389. 
*Nautilus. , 
*Proc. Acad. N.S. Phila., 1892, p. 404, (no description). 
