13 



The interior of many species is adorned with 

 very brilliant colours, such as shades of purple, 

 violet, copper, pearl, gold, and frequently irides- 

 cent, although the colour of the epidermis which 

 always covers the shells, is of a dark or black, 

 brown, chestnut, ferruginous, or olive, &c. Many 

 produce pearls or pearly and coloured excrescen- 

 ces, some of which are very beautiful; their 

 variegated nacre might be made useful and 

 profitable in the arts. In places out of the lime- 

 stone region, these shells are gathered for the 

 purpose of making lime. The animal is usually 

 white, sometimes yellow or saffron coloured ; and 

 is very long lived. 



FAMILY PEDEFERIA. 



Shell bivalve, equivalve, inequilateral ; animal 

 having a large compressed foot, tendinous, not 

 byssiferous; two very short syphons, or sometimes 

 instead, two apertures; the anus under the 

 ligament ; hinge dentated or lamellated. 



This family includes all the bivalve shells of 

 the Ohio, such as the genera Unio, Anodonta, &LC. 

 of authors ; as well as my new genera separated 

 from the Unio. I have divided it into several 

 sub-families, of which five are found in the Ohio. 

 2* 



