THE NAUTILUS. 31 



deal like putris, but smallish and spire longer; whorls con- 

 vex. It seems to be a good species. I have also seen it from 

 Alexandria, La., in the Binney and Bland Collection. 



(17.) S. stretchiana Bland. I have seen this from San Francisco, 

 Cal. (G. W. Michael), sent by Mr. Singley. It seems to be 

 a small species of the putris group, allied to S. parvula 

 Drouet, of Europe. Reddish-horn, not very shiny, striate, 

 spire rather large. In the Binney and Bland Collection, 

 one from Washoe Co., Nevada, looks rather like avara, at 

 least in color ; but another from Oregon is brown and 

 resembles the putris group. There is a form major Ancey, 

 ms. (sine descr.), nearly twice the size of the type, recorded 

 by Yarrow, from Pagosa, Colo. 



THE SHELL BEARING MOLLUSCA OF MICHIGAN. 



BY BRYANT W^ALKER, DETROIT, MICH. 



Caryehiuni exiguum Say. Common every vvhei'e. 



C. exile H. C. Lea. Although not as common as C. exiguum, 

 the localities where this form has been found indicate that it will be 

 found generally distributed over the state. 



Limncea stagnalis L. PI. I, fig. 6. 



Occurs all over the State, often in great abundance. An extreme 

 form, in which the body whorl is obtusely angulated, and the aper- 

 ture much enlarged, from Houghton Lake, Roscommon County, is 

 shown in fig. 6. 



L. stagnalis jugular is Say, PI. I, figs. 1, 2, 3. 



I think this form is entitled to varietal rank. It is not as com- 

 mon as the typicpl form and seems to occur usually by itself Fig- 

 ures 1, 2 and 3 from Black Lake, Presque Isle County, maybe 

 referred here ; but the expansion of the lip, especially of fig. 1, is not 

 typical, and is probably due to some peculiar local conditions. All 

 the specimens from this locality are a pure translucent white. The 

 Physa fragilis of Mighels is probably a similar case in another 

 genus. 



L. stagnalis sanctoiniaricE. PI. I, figs. 4 and 5. 



