No. 89.] 107 



ORTHOCERAS INDIANENSIS (n.s.). 



Shell extremely elongate, very gradually tapering; section circular. Septa some- 

 what deeply concave, the concavity equal to one-third the diameter, distant from 

 each other from one-fourth to one-third the diameter. Siphuncle central or sub- 

 central, small; outer chamber subfusiform and constricted towards the aperture. 

 Surface imknown. 

 The specimens are numerous, occurring in fragments with diameters varying 



from one-tenth of an inch to nearly two inches. The condition of the specimens 



is precisely the same as that of the Goniatites at the same locality. 



This species very closely resembles 0. marcellensis, but tapers less abruptly. 



In specimens of the same size, the number of septa does not differ in the two 



species. 



Geological formation and locality. In the same strata with Goniatites oweni 



and G. rotatorius ; at Rockford, Indiana. 



PUGIUNCULUS.? (THECA) ACULEATUS ( n. s.). 



Elongated obtusely triangular bodies, having one side nearly flat, and the other 

 two sides meeting at a very obtuse angle, and slightly incurved towards that angle, 

 the flat side being convex in the direction of the length. Aperture obtusely triangu- 

 lar, and a little thickened on the straight side at the lateral angles- 

 It is with hesitation that I refer these bodies to any known genus. 

 Geological formation and locality. In the Goniatite limestone at Rockford, 

 Indiana. 



DENTALIUM ACICULATUM (n.s.). 



Small, slender, cylindrical, gently tapering and slightly incurved tubes, with 

 striated surfaces. In general appearance these tubes resemble minute Orthoceratites ; 

 but they are destitute of septa, and incurved towards the upper extremity. 



Geological formation and locality. In the Goniatite limestone : Manlius, N.Y. 



BELLEROPHON LINEOLATUS (n.s.). 



Shell subglobose : volutions broadly rounded on the back, not carinate, the last 

 one much expanded ; aperture somewhat semicircular, and extended at the 

 lateral angles; umbilicus small and neatly rounded. Surface marked by longi- 

 tudinal elevated and rounded striae which are somewhat alternate in size, and 

 crossed by similar finer striae, giving a beautifully cancellated structure. 



There is a slight depression and an arching of the striae along a narrow dorsal 

 line. Length about half an inch, with a width of one quarter of an inch at the 

 junction of the labrum with the volution. 

 This species bears a close resemblance to a species in the Hamilton group in N. 



York. 



Geological formation and locality. In the Goniatite limestone at Rockford, Ind. 



BELLEROPHON CYRTOLITES (n.s.). 



Shell subcuneiform; the first volutions narrow, expanding more suddenly to- 

 wards the aperture : volutions contiguous, but slightly embracing, somewhat 

 acute, angular upon the back, and the outer half of the last one obtusely angular 

 at the umbilical margin. Aperture rhomboidal, with a deep notch at the dorsal 



