MUSSELS OF BIG BUFFALO FORK OF WHITE RIVER. 15 



Cob shell., rabhWs foot., Quadrula cylindy^ica {Say). — The first 

 one, a dead shell, was taken at station 5, From here on it was, on 

 the whole, rather common. The greatest number taken at any one 

 place was 13, at station 25. In all, 59 examples were secured. At 

 the pearler's camp it was called " cob shell." Along the Wabash it 

 is known as " rabbit's foot." The nacre of all found is white, though 

 many are more or less stained. Several were beautifully marked by 

 green triangular marks and some were semitranslucent. None was 

 young and most were of medium size. The species has no commercial 

 value. 



It was found at the following stations: 5^ one dead; 14, com- 

 mon; 15, common; 16, common; 17, abundant; 18, common; 19, 

 common; 21, common; 24, common; 25, common; 26, scarce. 



Rock mussel, wasliboard, Quadrula undulata {Barnes). — Common 

 to abundant throughout the part of the river examined and repre- 

 sented in the collection by 61 shells. The shells are of the same 

 general type, medium in size and rather inflated. None is so com- 

 pressed as the fine examples to be found in northern Indiana and 

 Ohio and none so markedly inflated as to suggest plicata. Within 

 the limits suggested there is some variation in the degi-ee of inflation. 

 Those obtained at station 16 are somewhat flat, and one is almost 

 smooth. One obtained at the Jack Pot mine is markedly elongate 

 as compared with the others, but not conspicuously so when com- 

 pared with large series from elsewhere. The shells collected at 

 station 26 are considerably eroded. The greater number of these 

 shells exhibit well-marked costa? on the posterio-dorsal slope, with 

 deep furrows between them. High ribs extending ventrad from the 

 posterior slope and separated by deep furrows are also common. In 

 these features the shells resemble a common type of the west and 

 south and approach the style represented by Say's figure of Vnio 

 costatus. At the pearler's camp they were called " rock mussel," or 

 •' washboard." 



Wiere this species attains good development it is a good commer- 

 cial species, but the Big Buffalo shells are small and of poor quality. 



It was found at the following stations: 1, most abundant; 2, 

 scarce; 16, abundant; 17, abundant; 18, most abundant; 19, abun- 

 dant; 20, common; 21, abundant; 23, scarce; 24, common; 25, abun- 

 dant; 26, abundant. 



Vnio gihhosus {Barnes). — Common; represented in the collection 

 by 77 specimens. As a usual thing only a few shells were obtained 

 at a station. The greatest number obtained at one place was 10, col- 

 lected at station 24. The most common form is the familiar medium- 

 sized shell with violet nacre. Those obtained at station 3 and those 

 collected at station 12 are large shells with white porcelaneous nacre. 

 The five examples taken at station 6 are dwarfed specimens with 



