GASTROPODA. 1067 
Holopea excelsa,] 
HoLopra EXCELSA, ”, Sp. 
PLATE LXXIX, FIGS. 11 and 12. 
Similar to H. concinnula but larger and relatively higher in the spire, with the aperture more 
oblique (about as in H. rotunda), the whorls scarcely so ventricose, and the umbilicus much smaller and 
probably closed entirely in the shell. Perhaps it is not distinct from H. paludiniformis Hall, but if we 
may rely on Hall’s figures of that shell, it differs, excepting the umbilicus, from H. eacelsa about as H. 
concinnula does. 
Formation and locality—Fusispira bed of the Trenton group, Wykoff, Sumner and Hader, Minnesota. 
Oollections.—Geological and Natural History Survey of Minnesota; E. O. Ulrich. 
Museum Register, No. 285. (A crushed specimen somewhat doubtfully referred to this species.) 
Hotopea PALUDINIFORMIS Hall. 
(Not figured.) 
Holopea paludiniformis HAL, 1847, Pal. N. Y., vol. i, p. 171, pl. xxxvu, figs. 3a, 3b. 
A small specimen, apparently of this species, was collected by Mr. E. O. Ulrich in the Clitambonites 
bed of the Trenton group near Cannon Falls, Minnesota. The specimen is imperfect at the mouth and 
shows clearly that it has a small umbilical perforation, so it may belong to some other species, unless the 
prevailing impression that H. paludiniformis has no perforation proves erroneous. With this specimen a 
larger one was found which possibly is the same. We think not, however, since it has a wider umbilicus 
and an impressed suture, reminding one in both features of H. appressa. 
HoLopEa PYRENE Billings. 
PLATE LXXIX, FIGS, 13—18. 
Holopea pyrene BILLINGS, 1862, Pal. Foss., vol. i, p. 27. 
Holopea perundosa SARDESON, 1892, Bull. Minn. Acad. Nat. Sci., vol. iii, p. 336. 
Shell obliquely turbinate, spire depressed conical, rising but little above the top of the last whorl; 
whorls three or four, the inner ones appearing slender, the last somewhat ventricose, subovate in cross 
section, the vertical diameter considerably greater than the transverse, the upper side of the outline more 
obtuse than the lower; umbilicus large; suture deeply impressed; aperture slightly oblique; whorls crossed 
by deep concave undulations separated by rather sharp ridges; lines of growth very obscure in the speci- 
mens studied, which seem to be, at least in part, casts of the exterior. Width 33 mm., hight about 
27 mm. ~ 
It may be that Dr. Sardeson was justified in separating the Minnesota species here described from 
H., pyrene, especially since Billings says that his specimen, which does not show the under side, has a form 
“much like H. obliqua Hall,” and comes from a lower geologic horizon than our specimens. It has, how- 
ever, seemed so unlikely to us that such an extravagant character as the strong undulations of the whorls 
would appear in two distinct species of the same genus, that we have decided to refer the Minnesota spec- 
imens to Biilings’ species until the latter has been shown to be distinct. 
Formation and locality.—Lower part of Fusispira bed, near Cannon Falls, Minnesota. 
Collection.—E. O. Ulrich. : 
Honopga parvua, 7. sp. (Ulrich.) 
PLATE LXXIX, FIG. 19. 
Shell small, 6 to 10 mm. in width, the hight equalling about three-fourths of the width; spire 
depressed conical; whorls four, including two very small ones at the apex, neatly rounded, subcircular in 
