DESCRIPTION OF NEW SPECIES OF FOSSILS 

 FROM THE CALCIFEROUS FORMATION.* 



By C. D. WALCOTT. 



PLATYCERAS Conrad, 1840. 



Platyceras minutissimum Walcott. 



Shell small, subspiral, regularly arcuate from near the aperture to the apex, 

 making nearly three-fourths of one volution ; section subelliptical, somewhat 

 carinate upon the dorsum. Two transverse depressions upon the sides, give a 

 slight undulation to the body of the shell. 



Surface marked by faint longitudinal striae. 



Formation and locality. Calciferous formation, Saratoga Co., N. Y. 



METOPTOMA Phillips, 1836. 

 Metoptoma cornutaporme Walcott. 



Oval, subconical ; apex incurved, depressed, extending beyond the anterior 

 margin ; distance from the posterior margin to the apex twice the width. The 

 most elevated point is about two-thirds the distance from the posterior margin 

 to the apex ; from this point the outline curves regularly to the posterior margin 

 and anteriorly to the apex. Outline from the apex to the anterior margin con- 

 vex. Length, nine lines ; width, four and one-half lines. 



Surface, with narrow concentric ribs, one-half a line apart ; finely striate 

 vertically. 



Formation and locality. Calciferous formation, Saratoga Co., N. Y. 

 CONOCEPHALITES Zenker, 1833. 



CONOCEPHALITES CALCIFEROUS Walcott. 



Head semicircular, convex. Glabella truncato-conical, moderately convex ; 

 width at the base nearly equal to the length ; anterior margin straight, abruptly 

 rounded at the angles ; sides straight and regularly converging ; the posterior 

 and middle glabellar furrows oblique and well marked, the anterior furrow 

 indicated by a smooth line upon the granulose outer shell, and a slight depres- 

 sion when the outer shell is removed. Occipital furrow broad and well 

 impressed. Occipital ring narrow at the sides, widening at the centre to form 

 the base of a strong slightly curved spine, which extends obliquely backward ; 



* Advance copies of this paper were printed January 3, 1879. 



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