316 PALiEONTOLOGT OF OHIO. 



PTEROPODA. 



Genus COJsIULAKIA, Miller, 1818. 



(Sowerby's Min. Con., .) 



CONULARIA MICRONEMA, Meek. 



Plate 18, flgs. la, 6, c, d. 



Conularia micronema. Meek (1871,) Proceed. Acad. Nat. Sci., Philad., XXIII, 84. 



Shell elongate-pyramidal, with the sides equal and diverging from the 

 apex at an angle of about sixteen degrees ; lateral surfaces nearly flat, and 

 without any mesial furrow, but sometimes showing a very faint, slender 

 mesial ridge, that becomes nearly or quite obsolete toward the smaller 

 end ; each of the four angles a little rounded and provided with a shal- 

 low, moderately distinct longitudinal furrow. Surface with numerous 

 extremely small, closely crowded transverse striss, of very nearly the 

 same size on all parts of the shell ; striae gently arching forward as they 

 cross the side, and scarcely interrupted at the little mesial longitudinal 

 ridge, minutely crenate, and separated by extremely slender linear fur- 

 rows, numbering fifteen in the space of one-tenth of an inch, on all parts 

 of the surface ; crenulations of striae twelve to fifteen in one-tenth inch. 



Length of a specimen broken at both ends, with a diameter of 0.96 

 inch at the larger end, and 0.46 inch at the smaller, 2.30 inches. 



This species is remarkable for the extreme fineness and closely crowded 

 uniform character of the transverse striae on all parts of the surface. I 

 know of no other species resembling it in other respects, with near such 

 fine, crowded striae. At a little distance these lines are often entirely 

 invisible to the unassisted eye, and it requires the aid of a magnifier to 

 see them distinctly. The furrows between these striae are mere impressed 

 hair lines in which no crenulations are visible in the specimen. 



Locality and position: Sciotoville, Ohio. Waverly or lowest division of the Carbon- 

 iferous. ■ ^, . , ^ L' — 

 CONULAEIA NeWBEEEYI, fi^V''" 



Plate 18, figs. 2a, 6. 

 Ckmularia Newberryi, Hall.* 



Shell attaining a moderately large size, presenting the usual elongate- 

 pyramidal form, with equal or subequal lateral surfaces diverging from 

 the apex at an angle of about sixteen degrees ; sides a little convex, and 



* I have not been able to find Prof. Hall's description of this shell, and only know 

 that the form here described has been generally identified with it. 



