14 PALiEONTOLOGY OF NEW-YOEK. 



Fig. 6 a. Ventral view of the specimen. Fig. 6 h. Lateral view. Fig. 6 c. Section of same. 



Position and locality. The specimen was found at Lockport, near the upper part of the 

 sandstone. 



398. 26. ORTHOCERAS (n. sp.). 



Pl. IV (bis). Fig. 7 a, b. 



Subcylindrical, straight ; section elliptical ; siphuncle subdorsal ; septa closely arranged and 

 highly arched. 



This species is known only in a single fragment, but it is clearly distinct from any heretofore 

 described. The septa are distant about one-eighth the narrowest diameter of the shell. 



Fig. 7 a. Lateral view of the fragment. Fig. 7 b. Section showing position of siphuncle. 



Position and locality. In the upper fossiliferous portions of the rock at Lockport. 



(Collection of Col. Jewett.) 



399. 27. ORTHOCERAS MULTISEPTUM (n. sp.). 



Pl. IV (bis). Fig. 8 a, b. 



Cylindrical, gradually tapering ; septa distant one-sixth to one-seventh the diameter. 



The septa are slightly more distant than in the preceding species. I have not been able to 

 ascertain the position of the siphuncle, or convexity of the septa. It is possible that this and the 

 preceding are the same species, and the oval form in that one may be due to pressure. 



Fig. 8 a. A fragment of a small specimen, showing a part of the outer chamber. 

 Fig. 8 b. A fragment of a larger specimen, showing the commencement of the outer chamber, 

 with a narrow one at the termination of the others. 



Position and locality. In the upper fossiliferous part of the rock at Lockport, and associated 

 with Pleurotomaria at Medina. {State Collection.) 



These cephalopods are extremely rare, and few specimens have ever been found. 



400. 2. CYTHERINA CYLINDRICA (n. sp.). 



Pl. IV. Fig. 8 a, b. 



Elliptical, elongated, very convex. 



This species being preserved in sandstone, presents no characters beyond its general form. It 

 is readily identified by its oval rather elongated form and great convexity, which, w'hen both 

 valves are joined, would give an almost cylindrical form to the shell. 



Position and locality. Associated wuth Lingulce and other fossils at Medina, Orleans county. 



