31 I PALAEONTOLOGY OF NEW-YORK. 



PLATE LXXI. 

 Fig. 1. A frafinicnt of a larpe specimen preserving a part of the outer chamber, with about 

 fourteen of the first chambers above. 



Fig. 5. A specimen showing a longitudinal section, apparently of the same species, the septa 

 being proportionally a little more distant. 



Geological position and locality. In the peiitamerus limestone of the Lower Hel- 



derberg group : Albany and Schoharie counties. 



Oi'tlioccias i-ijn>-iduiii ( n. s.). 

 Plate LXX. Fio. 3 n - rf. 



Shell elongate, gradually tapering; section circular. Septa moderately 

 convex, distant from each other about one-siJ^th the diameter of the 

 tube. Siphuncle central, narrow in its passage through the septum. 



Surface marked by fine sharply-elevated equal transverse striae"^ 



This fine species is only known in the fragment figured, which preserves more 



than forty of the septa. The surface strijE are more finel}' and sharply marked than 



in any other species that has come under my observation. 



Fig. 3 a. A fragment of this species, having the shell almost entirely removed. 



Fig. 3 6. A continuation of the same specimen. 



Fig. 3 c. Transverse section, as shown in the line of fracture of fig. 3 6. 



Fig. 3 d. Enlargement of the striae. The position of the figure represents the striae in the 

 reverse of their natural relation, which is horizontal. 



Geological position and locality. In the pentamerus limestone of the Lower Hel- 



derberg group : Herkimer county. 



Oitlioceras snbtextile ( n. s.). 



Plate LXXI. Fia. 2. 



Shell gradually tapering : siphuncle subcentral : septa unknown. 

 SoBFACE marked by strong transverse striae or low ridges, and by a much 



finer set of striae in the same direction, and the latter cancellated by 



a still finer set of longitudinal striae. 



A single fragment only of this species has been observed, but the peculiarity of 

 the surface marking seems sufficient to distinguish it from any other species. 

 Fig. 2. The specimen, natural size. 



Geological position and locality. In the lower part of the pentamerus limestone of 

 the Lower Helderberg group : Schoharie. 



