THE NAUTILUS. 63 
Carychium exiguum Say. Figs. 1, 2, 3. 
Shell cylindrical, the last two whorls of about equal diameter. 
Whorls 43. Aperture decidedly over one-third the total altitude. 
Outer lip sinuous, moderately thickened, very strongly arcuate at 
its upper outer portion. 
This is the common East American form, ranging from Maine 
southward and westward, the limits of its range not exactly deter- 
mined as yet. 
Carychium exiguum var. Mexicanum Pilsbry. Figs. 7, 8, 9. 
Shell cylindrical. Whorls 4}. Aperture equal to, or a trifle ex- 
ceeding one-third the total altitude of shell. Outer lip thickened at 
and below the middle by a very heavy deposit of callus upon its face. 
Lower fold of the columella sub-obsolete. Surface delicately striated. 
Orizaba, Mexico. 
Carychium occidentalis Pilsbry. Figs, 4, 5, 6. 
Shell distinctly conical, tapering. Whorls 5. Aperture very 
oblique, larger than in C. exiguum, the outer lip flatly expanded, 
thin, not at all thickened on its face. 
Portland, Oregon, is the only locality from which I have seen 
this species. 
Carychium exile H. C. Lea. Figs. 10, 11, 12, 13, 14. 
Sheil elongated. Whorls 5-5}. Aperture small, very oblique, 
about one-third the length of the shell. Outer lip more or less thick- 
ened. Surface closely, regularly and very distinctly striated. 
Eastern Pennsylvania (H. C. Lea); Kent, Ohio (Geo. W. Dean). 
Lea found this form on the Wissahickon Creek, near Philadelphia, 
but I have not been able to rediscover it there. 
Carychium exile var. Jamaicensis Pilsbry. Figs. 15, 16. 
Much elongated, similar to C. exile, but the surface smooth, not 
perceptibly striated. 
Jamaica. 
LIST OF SHELLS FROM THE VICINITY OF MINGUSVILLE, MONTANA. 
BY HOMER SQUYER. 
Many of the smaller forms were picked out of fine river drift 
found along the banks of Beaver Creek, a tributary of the Little 
Missouri, after the subsidence of the freshets. 
