84 Cincinnati Society of Natural History. 



in 48°, we reach between these points the limits of distribution so far 

 as now authenticated. 



Through the industry and success of our Secretary, Dr. J. M. Craw- 

 ford, who discovered this mollusk during the past summer, on the 

 western side of Green Bay, in upper Michigan, and who kindly obtained 

 and brought home living specimens, we are enabled, not onh"^ to clear 

 up slight errors in reference to the shell, but to describe the animal 

 accurately, as well as to give a full discussion of its an atom}'. The 

 adult shells from the Green Bay locality much exceed in size those 

 described by Say, and figured by Haldeman and Binney, as the average 

 length is two inches, and specimens frequently reach that of two and 

 three-eighth inches, or nearly 60 mill., while Say's specimens were less 

 than 45 mill., in length. Many of the specimens collected by Dr. Craw- 

 ford, also attain a diameter of more than one inch, so that, considered 

 in reference to cubic capacity, they are much larger than the specimens 

 described by Say, or figured hy either Haldeman or Binney. The 

 color of the shells is a uniform yellowish brown, with none of the highly 

 ornamental outside tints given in Prof. Haldeman's pi. 3., figs. 1 and 3. 

 The inside of the shell is nacreous, and dark purple, or purplish brown 

 when the shell is somewhat thin. The columellar callus is carried 

 around, and spread widely over the inner and upper center of the body- 

 whorl, thickening it, and rendering this part of the shell white interiorly. 

 Tho lines of growth give the whorls a slightly undulated appearance; 

 and these have a tendency, in a few specimens, to be broken up trans- 

 versely, on a small area of the front of the shell, directl}' over the aper- 

 ture, giving that portion of the body-whorl a somewhat wrinkled ap- 

 pearance. A few very minute transverse striae may be seen with a 

 good magnifier. The body-whorl makes up the greater part of the shell. 

 Above this it tapers rapidly to the acute apex. 



Animal. 



The head, rostrum, tentacles and upper and lateral surfaces of the 

 animal are of a dirty yellow, dotted with lighter, j^ellowish white pig- 

 ment spots or granules of irregular form. The rostrum is deeply cleft 

 in front, the two lobes being rounded anteriorly and laternll}'. The 

 oral aperture is situated in the rostral cleft; the tentacles are triangu- 

 lar, attenuated at their extremities, and have a ridge-like process con- 

 tinued from their inner angle upon which the eyes are situated, close 

 to the base of the tentacles; these are long enough to project laterally 

 and anteriorly beyond the lobes of the rostrum. The foot is wide and 

 short, obtusely rounded in front, slightly attenuated and more pointed 



