72 FIFTEENTH REPORT ON THE CABINET OF NAT. HISTORY. 



Geological formation and locality. In limestone of the Upper Helder* 

 berg group at Clarence-hollow, Erie county, N.Y. 



CYRTOCERAS METULA (n.s.). 9 /• 7 

 This species is very gradually curving ; the specimen examined 

 making, in a length of two inches, less than one -eighth of one 

 volution. The smaller extremity of the fragment has a diameter of 

 three-eighths of an inch; and the larger extremity, which is at the 

 commencement of the outer chamber, has a dorso-ventral diameter 

 of three-fourths of an inch, while the transverse diameter is nearly 

 an inch. The septa are numerous, and about a line distant from each 

 other on the middle of the specimen. 



This specimen contrasts strongly with the preceding in its proportions, 

 and may be readily distinguished by its much more rapid expansion towards 

 the aperture. 



Geological formation and locality. In limestone of the Upper Helder- 

 berg group at Clarence-hollow, associated with the preceding species. 



GENUS APLOCERAS ( D'Orbigny). 



APLOCERAS (CYRTOCERAS) LIRATUM (n.s.). "^ [. Q 

 A fragment, clearly appertaining to this genus of D'Orbigny, 

 has been found in the Goniatite limestone. The specimen preserves 

 three or four of the septa and a part of the outer chamber : the 

 section is circular; the septa are distant a little more than an eighth 

 of an inch. The surface is longitudinally fluted by regular ridges, 

 as in the typical species of the genus. 



Geological formation and locality. In the Goniatite limestone at Man- 

 lius, Onondaga county, N.Y. 



GENUS GOMPHOCERAS (Sowerby). 



GOMPHOCERAS BETA ( n. s.). J V ^ 

 A small species, attaining the length of about an inch and a half. 

 The form is ovoid; the seven or eight chambers before the last 

 measuring about three-fourths of an inch, and the outer chamber 

 as much more. The greatest diameter, when not compressed, is 

 nearly half as great as the length. The septa are thick, and the 

 siphuncle marginal. 



Geological formation and locality. In the Schoharie grit at Schoharie. 



[September, 



