2 University of Michigan 



not more than ten feet wide, two or three feet deep, swift, and 

 filled with pebbles and small stones. Assiduous search in other 

 branches of the same stream failed to add to the number of 

 specimens, which was due probably to the fact that the greater 

 part of that section of the county is under cultivation, and the 

 natural streams have been cleared of vegetation in order to be 

 used as drainage ditches. 



The second species new to ^Michigan has been identified by 

 Bryant Walker as Flanorbis dilatatiis biiclianciisis (Lea). Two 

 large specimens and a number of small ones were collected 

 near Harbert, Berrien County. These were all taken from 

 dead leaves and sticks submerged in a small pond above a dam. 

 The largest specimen measures as follows : greater diameter 

 4.25 mm., lesser diameter 2.75 mm., altitude 1.5 mm. This 

 differs from Lea's bncJunicnsis'^ in its greater size and distinctly 

 angular aperture due to the strong carina. It agrees in all 

 points with a specimen from New Philadelphia, Ohio, with 

 which it has been compared. The surface sculpture of incised 

 revolving lines cannot be compared with that of P. buchanensis 

 since the sculpture is not mentioned in the original description. 

 The original specimens of P. buchanensis were from "near 

 Cincinnati, Ohio," and the only other record until the present 

 one was Ncav Philadelphia, Ohio."' 



The typical P. dilatatiis was described by Gould" from Nan- 

 tucket and Hingham, Massachusetts. According to available 

 records the range of the typical form extends from New Eng- 

 land to Florida, north to Ohio and Ontario, and west to the 

 Mississippi. A single record from Texas indicates a possible 



^Lea, Obs., IV, i8, p. 6. W. G. Binney, L. & F. W. Shells X. Am., Pt. II, 

 1865, p. 127, fig. 212. 



sSterki, Proc. Ohio St. Acad. Sci., Vol. IV, 1907, Pt. 8, p. 383. 



" Inv. Mass., 1841, p. 210, fig. 140. "In July, 1840, Mr. T. J. Whittemore, 

 found it in great numbers at Hingham. ..." 



