CLASS ANNULATA. 



ORDER SEDENTARY ANNULATA. 



FAMILY DORSALIA. 



GENUS SILIQUARIA. Lamarck, 



S. Claibornensis. Plate 1. Fig. 1. 



Description. Shell round and spirally tapering, longi 

 tudinally and indistinctly furrowed; fissure inarticulated. 



Observations. Not having obtained a complete specimen, 

 I am unable to give a perfect figure of this species. Among 

 the fractured pieces are two which, by two or three rapid 

 turns, form nearly a complete apex. In some, transverse 

 septa, as mentioned by Lamarck, are found. These are 

 very thin and hemispherical, the convex side being to 

 wards the apex. In some fragments the fissure is closed 

 on the inside. I presume this takes place below the upper 

 septum; but I cannot decide upon the few specimens in 

 my possession. The furrows on some specimens are very 

 perceptible, on others obsolete. One of the fragments is 



