275 



Lampsilis iris has a well marked tendency in the lakes and Outlet 

 to produce pearls and baroques; but these are too small to be of any 

 value. 



9. Lampsilis suhrostrata (Say). 



Lampsilis suhrostrata reaches its best development along the muddy 

 shores of lagoons, not being perfectly at home either in swiftly flowing 

 streams or in perfectly quiet lakes, although occasional examples may bo 

 found in either. It is considerably more abundant in Lake Tippecanoe 

 and Upper Fish Lake than in any other Indiana lakes examined. Along 

 the edges of the Mississippi sloughs it is fairly common and reaches a 

 large size, often distinguished with difficulty from Lampsilis fallaciosa 

 except for the thinness of the shell and the black epidermis. It is rare 

 in Lake Maxinkuckee, only a few examples having been obtained from 

 the mussel bed near Norris Inlet. It is much more common in Lost Lake 

 in the large bed along shore south of the Bardsley cottage. Mr. Blatchley, 

 in a short report on the mollusks of the lake (25th annual report. 

 Department of Geology and Natural Resources of Indiana, 1900, p. 250), 

 says of this species: "Not common in the main lake; more so in the muck 

 and mud along the margins of Lost Lake, where a well-marked variety, 

 with a larger and broader beak, was taken. A specimen of this was 

 sent, among others, to Mr. Chas. T. Simpson, of the Smithsonian Insti- 

 tution, for verification. In his reply he says: 'The variety of suhro- 

 stratus which you send is, so far as I know, confined to northern Indiana. 

 It is quite remarkable, and would seem to be almost a distinct species. 

 I have seen quite a number of specimens of it, and at first thought it 

 a variety of U. nasutus, but there seem to be intermediate forms con- 

 necting it with U. subrostratus.' " 



With the exception of the diiferences due to sex, all the Maxin- 

 kuckee and Lost Lake shells are very uniform in appearance, much more 

 so than L. luteola, and are hardly distinguishable from examples from 

 Lake Tippecanoe, Upper Fish Lake, or a specimen collected in the Wa- 

 bash River at Terre Haute by Dr. J. T. Scovell. They are dark brown 

 in color with very faint rays. The species appears to be rare in the 

 Tippecanoe River at Delong. One example was obtained there, which 

 is somewhat shorter and stouter than those of the lake, and not so badly 

 stained; it shows faint rays posteriorly. The Lost Lake shells are some- 



