CALCIFEEOUS SANDSTONE. 9 



FOSSIL SHELLS OF THE CALCIFEROVS SANDSTONK 



Plate III. 



The shells observed by myself in this rock are all univalves, though Mr. Vanuxem 

 mentions the occurrence in it of an Jitrypa in the Mohawk valley, and one or two species 

 of LingtUa have been found in the same. No specimens of the latter have come under my 

 own observation, either in the rock itself, or in any cabinet or collection of fossils which I 

 have examined. Mr. Conrad gives the following species : 



7. 1. LINGULA ACUMINATA.* 



Lingula acuminata. CoiniAii, Annaal Report of 1839, p. 64. 



Shell acute, acuminated at the apex, somewhat gibbous on the umbo, and compressed 

 laterally ; basal margin rounded. Length \ of an inch. 



Position and locality. In a boulder or loose mass of the Calciferous sandrock ( See Van- 

 vxem's Report, p. 35 ) . 



a 1. EUOMPHALUS UNIANGULATUS (n. ip.). 



Pu in. FigB. 1, 1 m. 



Planorbicular, discoidal ; volutions angular above, roimded below ; spire scarcely rising 

 80 high as the angular ridge upon the upper and outer edge of the last whorl ; lower side 

 concave ; upper surface striated obliquely from within outwardly towards the edge of the 

 whorl ; lower surface even, smooth. 



This shell presents all the essential characters of species of this genus from the Mountain 

 limestone : it is prominently marked by the single angular ridge upon the upper and outer 

 edge of the whorls, which becomes obsolete towards the apex. The specimen is a cast ; 

 but the strise (which are too strong in the engraving) still remain impressed upon it on the 

 upper side, while on the lower side it is smooth. The remains of several specimens were 

 found in a porous sandy chert or hornstone. 



* Judging from Bome manuscript notes of Mr. Conkad, in my possession, I am 

 inclined to think he afterwards referred this shell to the L. atlenuata of Sowerby. 

 Having never seen a specimen from the sandstone, I can only give this figure from a 

 drawing of Mr. Conkad (the original specimen being now in the possession of Mr. 

 VAirnxEM), in the hope of calling the attention of observers to the subject, and, if 

 poaaible, of obtaining specimens which may be satisfactorily compared. 



[ PAL.E0NT0L0GY.] 2 



LiBcvU •eniniiuta 



