

. , , .,, ; . 



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 



