12 Cincinnati Societi/ of Xatiirnl /listori/. 



Genus Beyrichia (McCoy). 

 Bkykichia persulcata, n. sp. (Plate VII., fig. 6.) 



[Ety. —Pfirsulcfttu)', strongly suleated.] .-' 



Lengtli of large specimen, .02; breadth, .015 inch. 



Carapace A'ery minute, sub-reniform to semi-circular, longer than wide, 

 the proportions being about as three to four ; dorsal margin straight, as 

 long as the vah'e; anterior and posterior extremities subequal : valve 

 marked by three transverse furrows, extending from the dorsal to the ven- 

 tral margin, which are deeply* and abruptly impressed, the central one be- 

 ing essentially central to the entire valve; anterior and posterior furrows 

 at their ventral ends, curving slightly towards each other. The ante- 

 rior, posterior, and posterior median lobes are nearly equal in size, the 

 latter, however, is somewhat more prominent ; the anterior median lobe 

 is of the same general form and dimensions as the posterior median 

 lobe, but is divided in the middle of its length into two nearly equal 

 parts, by a narrow, deep, and veiy abrupt furrow. Sui'face smooth. 



This is an exceedingly small and quite distinct species. It is pro- 

 bably most nearl}' related to Beyrichia regidaris^ Emmons, from which 

 it is distinguished by its comparatively stronger ridges or lobes, and 

 much more abrupt!}' depressed sulci, as well as by having the anterior 

 median lobe divided into two parts, instead of entire, as is the case in 

 that species. 



Formation and locality : found associated with Leperditia crepifor- 

 inis, at Covington, Ky, 



Collector : E. O. Ulrich. 



Genus Cvrtolites (Conrad). 

 Cyrtolites nitidulus, n. sj). (Plate VII., figs. 7, la.) 



[Ety — yuidulufi, neat, pretty.] 



Shell below the medium size; volutions two or three, rapidly increas- 

 ing in size, very slightly embracing; dorsum with a broad, flattened 

 carina; sides strongly convex, rounding more abruptly into the umbili- 

 cus than to the periphery; umbilicus moderately wide and deep; aper- 

 ture broadly cordate. Surface ornamented bv rather fine, rounded, 

 transverse striae, crossing the volutions from the umbilicus to the dor- 

 sum in a curved and obliquel}' backward direction; on the broad dor- 

 sal carina also the striae make a short backward curve. 



Greatest diameter of an adult example, 0.38 inch; convexity at the 

 aperture, 0.2 inch; number of transverse stri.e in the space of one tenth 

 of an inch, near the aperture, from seven to nine. 



