38 
THE NAUTILUS. 
all well defined. The older authors mixed them sadly; and we 
moderns are in some danger of drawing over-fine distinctions 
Still, the systematic zoologist who makes any voyages at all, must 
perforce sail between Scylla and Charybdis. The great art is to 
steer a middle course. 
Returning to our Orthalicus, we notice that the older collectors 
found only the zebra-striped forms in Florida, these being identical 
with the species so common in Jamaica, and known for many years 
under the names zebra Muller and undatus Bruguiere. 
Some authors have attempted to establish undatus and zebra as 
distinct species, but the last name was proposed for a medley of 
Achatinas and Orthalicus, not including the form now known as 
undatus; so it will be dropped from the lists entirely. The well- 
known Florida and West Indian species is O. undatus Brug., (see 
W. G. Binney’s works). It is not known from Mexico. 
Besides this form, we find in a number of localities in Southwest 
Florida, an Orthalicus with nearly white shell, spiral brown bands 
and occasional oblique stripes, but none of the zig-zag flames so 
characteristic of 0. undatus. This form was described by the writer 
in 1891, as follows: 
Orthalicus melanocheilus Val. (1833). 
One of the most distinct species of the genus, described originally 
from “New Spain” (i. e., the Middle American mainland). The 
Florida specimens differ from the Mexican and Central American 
in a number of characters and seem to me perfectly distinct as a 
geographic variety. 
0. melanocheilus var. Floridensis Pilsbry. 
Shell white or slightly stained with brown, having no longitudi¬ 
nal zig-zag flames. The body whorl has three narrow brown bands, 
the upper one often broken into spots. There is a black varix on 
the penultimate whorl, and one or two on the body whorl. The 
varices are generally not visible within the aperture, but the three 
spiral bands are conspicuous there. Lip bordered with blackish- 
brown ; columella white edged, but parietal callus deep brown. 
The types of this variety are from near Cape Sable, Florida. 
The synonymy of my variety includes : 
Bulimus zebra W. G. Binnev, Terr. Moll. U. S. Vol. IV, PI. 
lxxviii, fig. 12. 
0. zebra W. G. B. & T. Bid., Land and Fresh-water Shells of N. 
A., Vol. I, p. 216, figs. 370, 371. 
