GASTROPODA. 901 
Salpingostoma buelli.] 
The lateral view of a cast of this species given by Whitfield (op. cit., pl. VI, fig. 
18) does not agree with our specimens, the outer third of the last volution being 
much fuller in the figure, and represented as convex or straight almost to the edge 
of the aperture instead of deeply concave. Still, we cannot for a moment doubt 
that we have really described the species intended by Prof. Whitfield, since the 
majority of them are from the locality which furnished the original types, and all 
are precisely like specimens in the museum of the University of Wisconsin labelled 
in Prof. Whitfield’s hand as Bucania buelli. That the figure objected to may not 
be true to nature is indicated by the fact that it does not agree with his fig. 12 which 
is stated to be of the same specimen. It may be that the specimen is in part a 
cast of the exterior, which would account also for the presence of the radiating 
ribs. Not a trace of the latter is visible on any specimen seen by us that is truly a 
cast of the interior. - 
The surface sculpture of S. expansa Hall sp., of the Trenton of New York, is not 
well known, but casts of the interior are readily distinguished from those of this 
species, the volutions being less depressed, and subtriangular in section instead of 
subreniform. We have several fragments of a variety or closely related species from 
the Black River limestone of Kentucky, differing from the typical form of S. buelli, 
so far as the imperfect material will admit of judgment, in having a thicker shell, 
coarser surface markings, and smaller inner volutions when compared with the 
expanded aperture which is fully as large as S. buelli. The aperture also is not so 
abruptly turned outward dorsally. In the last feature it is more like S. expansa but 
the specimens are too small for that species and the volutions rounded on the back 
instead of subangular. Since the form is close to S. buelli we may designate it 
provisionally as var. kentuckyensis. 
The specimen represented by fig. 38 on plate LXVII is considerably smaller 
than any other of the species seen. The radiating ribs on the apertural 
expansion also are stronger than they should be in S. buelli. If these differences 
prove constant in other specimens they should be distinguished as a variety at 
least. 
Formation and locality.—In Minnesota S. bvelli is a rare fossil and so far known only from the lime- 
stones of the Stones River group, at Minneapolis, Cannon Falls and Old Concord. In Wisconsin, however, 
it is not uncommon and continues into the overlying limestones of the Black River group; Beloit and 
Janesville are the principal localities. In Illinois it occurs at Rockton and Dixon. 
Collections.—Geological and Natural History Survey of Minnesota; University of Wisconsin; Charles 
Schuchert; E. O. Ulrich; W. H. Scofield. 
Museum Register, Nos. 7293, 7318, ?5544. 
