18 MUSSELS OF BIG BUFFALO FORK OF WHITE RIVER. 



Lampsilis osarkensis (Call) var. — These specimens, unlike anything 

 we could find a figure or description of, more closely resemble a very 

 elongated Quadrula coccinea than anything else, agreeing with that 

 species both in texture of epidermis and color of nacre, which is 

 usually a rich rosy, though occasionally white. Examples were sub- 

 mitted to Mr. Bryant Walker, of Detroit, Mich., who has made a 

 special study of fresh-water mussels and identified them as above. 

 Mr. Walker remarks: 



Not typical. I have author's examples. But these agree with a shell I 

 have, so named, from Hardy. Taken by themselves, I should say that these 

 shells were Pleurohemas rather than a species of Lampsilis. They are not, 

 however, Simpson's elUptica. Alcoholic siiecimeus, which would enable the 

 generic place to be established, would be desirable. 



These shells also agree fairly well with specimens labeled ozark- 

 ensis in the Davenport Academy of Sciences, with which they have 

 been compared. 



This form was fairly common between stations 9 and 25, 20 exam- 

 ples having been secured. 



It was found at the following stations: 9, abundant; 13, scarce; 

 16, common ; 17, common ; 20, scarce ; 24, abundant ; 25, scarce. 



Lampsilis planicostatus [Lea). — Only two examples, both females, 

 one from station 2 and one from station 24. These were submitted 

 to Mr. Bryant Walker, who remarks, " A very interesting find. The 

 first record west of the Mississippi, I believe. Male examples would 

 be very desirable." The shells are elongate, somewhat resembling 

 a long flattened his, but without the brilliant radiation of that species. 



Spectacle case, Lampsilis lienosus (Conrad). — Seven examples of 

 this small species were found, all at station 8, and above Wolem. 

 All had the nacre deep purple, and one of the small females bore a 

 considerable resemblance to a large Lampsilis glans. A specimen was 

 submitted to Mr. Bryant Walker, who identified it as above. It is 

 a fairly common shell in southern streams. 



Spectacle case, hlach sand shell, LoMhpsilis rectus (Lamarck). — 

 Eathcr scarce. The first shells of this species were taken at station 6. 

 In all, 46 shells were secured. One dead shell had a colony of Pluma- 

 tella polymorplta growing on the inside of one valve. Most of the 

 shells of this species were of medium size and rather poor quality. 

 "Wliite-nacred shells are the rule rather than the exception, which is 

 the reverse of the situation in parts of the upper Mississippi, where 

 most of the shells are purplish. Where this shell attains large size 

 and has white nacre it is an excellent commercial species. At the 

 pearler's camp, station 15, it was called " spectacle case." In the 

 button trade it is known as the " black sand shell," while the former 

 name is applied to Margaritana monodonta. 



