58 THE NAUTILUS. 



ent region, and it may not be found in it at all, except, perhaps, near 

 its junction with the Holston. 



The presence of the species in the Cumberland offers a possible 

 explanation for its occurrence in the Ohio below Cincinnati and in 

 the Wabash. But that, of course, can not be definitely determined 

 until all of the southern tributaries of the Ohio, which head in the 

 mountains of West Virginia, have been carefully explored. If the 

 species should be found in the Big Sandy or the Great Kanawha, for 

 instance, it would seem likely that it reached the Ohio from that 

 source, even though, at the present time, it is not found in that river 

 above Cincinnati. 



But, however that may be, these new records tend to confirm the 

 opinion that the original point of dispersal of the species was in the 

 head-waters of the Tennessee system and that its present distribu- 

 tion is " rather the result of an ancient migration from the northeast 

 than one from the southwest." 



LAND MOLLITSCA AT TOLLAND, COLOBADO. 



BY T. D. A. COCKERELL. 



On August 23 and 24 my wife and I collected snails at Tolland, 

 in Gilpin county, Colorado, at an altitude of 8900 to 9000 feet. The 

 list of species, though short, may be of interest on account of the high 

 altitude, and the addition of one species to the Colorado list. 



Agriolimax campestris montanus (IngersoU). Variable, some very 

 dark. 



Vitrina alaskana Dall. Abundant. 



Euconulus fulvus alaskensis Pilsbry, abundant. 



Vitrea radiatula electrina var. alba (Jeffreys) Taylor. One. 



Zonitoides nrboreus (Say). Common under Populus tremuloides. 



Punctum pygmstum minutissimum (Lea). My wife found two by 

 carefully searching over dead leaves from the Populus tremuloides 

 zone. I believe only one specimen of this species has previously 

 been found in Colorado. Taylor (Monog. L. & F. W. Moll. Brit Is.) 

 cites Willow Creek and Cloudcroft, but the latter locality is in New 

 Mexico. 



Sphyradium edentuliim alticola (IngersoU) The adult is over 



