282 THE CHICAGO ACADEMY OF SCIENCES. 



white callus, bordered internally with very deep red or chest- 

 nut. The original locality was Poland, Ohio, and it has since 

 been found in Michigan, Utah and Nebraska, w-hich distribution 

 shows that it is likely to be found anywhere within the area 

 bounded by these localities. In the present region it has been 

 found in Mud Lake, Berry Lake (collected by Prof. W. K. 

 Higley), and in a ditch at Robey. 



Length, 20.00; width, 7.00; aperture length, 7.50; width, 3.75 mill. (8382.) 

 18.00; " 6.00; " " 7.00; " 2.50 " (8382.) 



ii2d. Limnaea reflexa exilis Lea, pi. xxxii, fig. 3; pi. xxxi, fig 3. 



Limn&a exilis LEA, Trans. Amer. Phil. Soc., Vol. V, p. 114, pi. xix, fig. 



82, 1837. 



Limncea reflexa variety BAKER, Trans. St. Louis Acad. Sci., Vol. IX, 

 p. 19; pi. i, fig. 3, 1901. 



Shell: Elongated, attenuated, thin; color light corneous or 

 honey-yellow; surface shining, growth lines distinct, crowded, 

 crossed by numerous very fine incremental striae; apex smooth, 

 very dark brown; whorls six to seven, flat-sided, rapidly in- 

 creasing in size, the last a little over one-third the length of 

 the entire shell; spire long and very much attenuated; sutures 

 impressed, margined below by a white band which is frequently 

 edged with chestnut; aperture elongate-ovate, slightly con- 

 tracted at the upper part; peristome sharp, thin, a rather heavy 

 callus within which is dark chestnut colored, the remainder of 

 the aperture being brownish or horn color; this color shows on 

 the outside as a light band; umbilicus closed; columella oblique, 

 not twisted, covered with a thin callus and with a light plait. 

 Length, 37.00; width, 11.00; aperture length, 14.00; width, 6.00 mill. 

 30.00; " 9.00; " " 13.00; " 5.00 " 



24.00; " 7.50; " " 10.50; " 4.50 " 



Distribution: Mississippi Valley, occurring also in Michi- 

 gan. 



Remarks: This variety in its typical form is almost dis- 

 tinct enough to constitute a species, and might be so designated 

 did not intermediate forms occur. The most pronounced dis- 

 tinguishing characters are the flat-sided whorls, particularly 

 the last, the long, steeple-shaped spire and the shallow sutures. 

 The peculiar twist, so characteristic of typical reflexa, is absent, 

 as is also the wide aperture. The animal is similar to reflexa; 

 the radula has the formula it+f+-V+i++t+l+ (40-1-40), 

 the teeth being the same as those of reflexa. 



This very distinct variety has been found only in the Cal- 

 umet River, so far as at present known. 



