THE NAUTILUS. 6/ 



NOTES ON VALVATA (LYOGYRTIS) BROWNII. 



BY II. F. CARPENTER. 



This species was found abundantly in CunlifF's Pond, at Elni- 

 ville, three or four miles south of Providence, adhering to stones 

 and empty valves of Unio complanatus. I discovered them in 1870 

 and kept more than two hundred specimens alive all summer in a 

 glass globe filled with water. I read a description of it under the 

 name of Amnicola Brownii before a meeting of the Providence 

 Franklin Society, Tuesday evening. Mar. 26th, 1872, and published 

 the same in the " Central Falls Weekly Visitor " the following week. 

 The specific name was given in honor of Dr. W. 0. Brown, who 

 was then President of the Society. Specimens was sent to the late 

 Geo. W. Tryon, who pronounced them to be a new species of 

 Valvata, subgenus Lyogyrus. Of late years they have been 

 gradually growing scarcer and the last time I examined the pond 

 I could find none, although I did not search very thoroughly. 

 Specimens of these shells are in the collections uf Mr. John Ford, 

 of Philadelphia, Mr. F. C. Baker, Mr. J. M. Southwick and several 

 other conchologists. The following is my original description: 



"Shell small, thin, translucent, of a light green color, when 

 divested of the thick, dirty epidermis which covers it, turreted, 

 elongate, composed of five gibbous whorls; operculated and umbili- 

 cated ; apex very obtuse ; suture very deep ; aperture nearly 

 circular, a little broader at the base; lip continuous, simple, the 

 superior edge of the inner lip not touching the preceding whorl^ 

 except in young specimens. Average size tV inch in length, by yV 

 in breadth. Diameter of aperture 2V inch. Full grown specimens 

 which are rare, attain a length of 25 inch. 



ON ANODONTA FLTJVIATILIS DILLW. 



The following letter received from Gen. de Peyster is interesting 

 as showing the facility Avith which fresh-water mollusks become 

 established in suitable spots. 



Upper Red Hook, N. Y., Sept. 19, '89. 

 Mr. de Peyster : 



Dear Sir : 

 At Dover Plains, Eastern Duchess Co., N. Y., last week I secured 

 sixty-three specimens of A. fiuviatills, including twenty-five or more 



