52 FIFTEENTH REPOKT ON THE C.^INET OF NAT. HISTORY. 



LOXONEMA? SUBATTENUATA (n.s.). 



A cast of a species having proportions nearly similar to Murchisonia 

 maia occurs in the Schoharie grit ; but the shell has tapered somewhat more 

 rapidly, the volutions are more ascending and less convex, and the form of 

 the aperture is subovate and narrowed below. The length from base of 

 aperture to top of the sixth volution is one inch and three-fourths, and the 

 diameter of the last volution is about five-eighths of an inch. 



In this species the volutions are less ascending, and the spire less atte- 

 nuate than in L. attenuata of the Lower Helderberg group, which in many 

 respects it resembles. 



Geological formation and locality. In Schoharie grit : Schoharie. 



LOXONEMA ROBUSTA ( n. s.). i/ jr^y 

 Shell robust, tereb reform. Spire rapidly ascending : length from 

 the base of aperture to summit of fourth volution, three inches; 

 above this there have probably been three or four volutions, add- 

 ing to the length about three-fourths of an inch. Volutions mo- 

 derately convex above the middle and flattened below, the last 

 one slightly more ventricose : the diameter of this last is nearly 

 an inch. 



This is a larger and more elongate species than any other of the genus in 

 the Upper Helderberg rocks. The specimen is a cast, having no surface- 

 markings ; but from the general character of the fossil, the flattened volu- 

 tions and close suture-line, I am induced to refer it to the Genus Loxo- 

 NEMA. A fragment of nearly the same proportions, and occurring in the 

 same association, has a banded suture, and is clearly distinct. 



Geological formation and locality. In Schoharie grit : Schoharie. 



-V LOXONEMA DELPHICOLA ( n. s.). ^ |^J 



Shell turritiform. Spire somewhat rapidly ascending : volutions 

 eight or more, flattened upon the sides, the last one slightly ven- 

 tricose. Aperture ovate, narrowed and attenuated below : colu- 

 mella thickened and extended below. 

 Surface marked by strong, not prominent, longitudinal strise, which 

 are bent slightly back for a short distance below the suture, and 

 continue in a nearly direct line almost to the base of the volution, 

 where they bend forward to the suture-line. Suture banded, or 

 .1 ' , [August, 



