OF THE FAMILY or NAIADES. 12 > 



tia. from which circumstance it is most probably in our cabi- 

 nets under another name. 



U. recta. This is the same with Barnes's prselongus, The 

 recta being described first should be retained. 



/ '. ntirjfarmis. This name cannot be retained, as Say had 

 previously described the shell under the name of cylindricus. 



U. glabrata. The habitat of this species is the Ohio river. 

 The description is too imperfect to identify it. and as the au- 

 thor acknowledges it has •• nothing remarkable," we may fairly 

 conclude it to be a variety of some one of the numerous spe- 

 cies described, a cariosus most probably. 



If. tuuuta. The author thinks this may be the >k/sn/iis of 

 Say. but the description answers much better to hi-; own recta 

 or Barnes's gibbomu, and is no doubt one of those. 1 do nol 

 believe the na.su/ u* has ever been found in our western wa- 

 ters*. 



U. ovata is the ovatus of Say. and inhabits the western wa- 

 ters, not the Susquehanna and Mohawk, as mentioned by La- 

 marck. Maton and Rackett described a British shell under 

 this name, which I believe to be only a variety of pictorum. 

 Those sent me from England by this name were certainly 

 mere varieties of the pictorum. 



U. rotundata. In most of our cabinets may be found a 

 beautiful shell, which we have thought to be of this species, 

 and have adopted the name. It does not. however, answer 

 to the description in some essential characters, and I i 

 therefore thought proper to describe the American -lull, and 

 ^ive it a new name. (See description of circultM.) Lamarck 

 gives no habitat. Ours is from the Ohio. 



('. littoraUa is from the Seine, and is described by Drapar- 

 naud. who says it resembles the U U. margaritifera? bul i< 

 much smaller. 



('. sc.mirugata. Description too short to identity it. Has 

 no habitat. 



Swamson n T I wo natuta, however, of Lamarck, I appi 



be found different" from Umoruuvhu of Say.— Zoo/. ///»••.-. VdL I pi 



\ 01.. in. — 5 i' 



