THE NAUTILUS. 



29 



I am rather at a loss to account for the occurrence of this European 

 species at this station. In both the localities previously reported, 

 that of Mr. II. E. Walter at Lincoln Park, Chicago, reported by 

 Mr. F. C. Baker,' and that of Mr. R. E. Call, at Flatbush, Brooklyn, 

 N. Y.,"'' the introduction of the species seems to be satisfactorily 

 traced to European plants cultivated in either green-houses or ponds. 

 But neither of these conditions certainly prevail at the present time 

 at the new locality, or to furnish a particularly satisfactory solution. 

 Mr. Vanatta suggests that, from the common use of these snails in 

 aquariums, and the pond being on private property once doubtless 

 well taken care of, it is very possible that the contents of an 

 aquarium may have been transferred to the pond at some time or 

 other. I have since made inquiries and am told that the pond has 

 contained gold fish for many years and that they are at present still 

 frequent there. So the evidence seems rather suggestive that this 

 solution may be correct. 



Suffice it, however, that the species has certainly become exten- 

 sively naturalized in this pond and is actually one of its most 

 prominent moUuscan elements. 



A NEW OBEOHELIX FROM COLOBADO. 



BY H. A. PILSBRY. 



We have recently received from the Hon. Junius Henderson a 

 series of shells collected by Mr. Albert Dakan, which seem to 

 represent a new specific form, which may appropriately be named for 

 Mr. Henderson, whose scientific works include an excellent account 

 ot the mollusks of Colorado. 



Oreohelix hendersoni, n. sp. 



The shell is solid, in shape much like 0. strigosa depressa (Ckll.), 

 the last whorl ani;ular in front of the aperture, becoming rounded in 

 the last half, shortly descending in front. First 2^ whorls rusty 

 brown ; the ground color then becomes very pale brown, and a 

 narrow darker band midway between sutures appears, usually not 

 continuing upon the last whorl, which is lighter, more cream-colored, 



1 Nautilus XV, p. 59, 1901. 



* Science, New Series, xvi, p. 65, 1902. 



