THE NAUTILUS. 
81 
NEW FORMS OF WESTERN HELICES* 
BY HENRY A. PILSBRY. 
The Pacific Slope has been proven by the researches of many 
collectors to be richer in varietal forms of Helices than any other 
part of the United States ; but although there are a large number 
of well-marked local varieties, there has been a tendancy to over¬ 
split them on differences of no racial value. The following forms 
are believed to be sufficiently individualised to require names. 
Although superficially some species such as arrosa, tudiculata etc. 
are very much like the European group Arionta, others like Cam - 
pylcea, and still others from Lower California are like Euparypha y 
it is the writers belief that the American forms are not closely allied 
to these European groups, but rather to the forms found in Japan, 
China and the Philippines, the resemblance to European types being 
a case of “convergence” of one character, the shell, and not extending 
to the less readily modified viscera. Other allies of the Californian 
group are the Hemitrochus of Florida and the greater Antilles, in 
Mexico another allied group, Lysinoe, is found ; but the genuine 
Californian type extends southward along the mountain axis as far 
as the Argentine Republic. All these American, and the East 
Asiatic groups are more nearly allied to each other than any of 
them are to the European Helices. 
The earliest name for this group of forms is the rather cumber¬ 
some term Epiphragmophora of Doring ; and it is proposed to use 
this in a generic sense, to supercede Arionta, A glaia and Euparypha 
of American writers. The history of all these snails and their 
names, with a discussion of their probable ancestry and migrations, 
will be found in the writer’s Guide to Helices, now in press. 
Epiphragmophora ellipsostoma n. sp. 
Shell globose-depressed, with low-convex spire, round periphery 
and almost covered umbilicus ; thin ; color a greenish straw tint, with 
one supra-peripheral brown band, surface shining, showing irregular 
growth wrinkles, and closely, somewhat spirally wrinkle malleate 
all over, much as in the thin forms of E. tudiculata; the spiral 
tendency of the wrinkles more marked below. Whorls 4, the apical 
1? forming a rather large nuclear shell; last whorl deeply descend¬ 
ing in front, a little constricted behind the basal lip. Aperture 
very oblique, short-elliptical, obliquely truncated by the penultimate 
whorl; peristome rather narrowly but evenly and well refiexed 
