﻿Cincinnati Society of Na/ural History. 



2. O. dvkki, S. A. Miller. 1875. 



Cm, Quar. Jour. Sci.. II. 125, fig. 11. four. Cin. Soc. Nat. Hist., 



III, 236, PL 7, fig- 7- 



0. meeki, S. A. M., Cin. Quar. Jour. Sci., II, 126, fig. 12. 

 0. hvmesi, S. A. M., Ibid., II, 126, fig. 13. J. Q S. N. H.. IV. 

 .319, PL 8, fig. 8. 



0. foster/, S. A.'M., Cin. Quar. four. Sci., II. 127. f. C.S. N. 1 1 .. 



IV, 319, PI. 8, figs. 7, V i. 



0. cincinnatiense, S. A. M., Cin. Quar. four. Sci., II. 127. f. C. S. 

 N. H., IV, 319, PI. 8, figs. 5, $a. 



0. ha/li, S. A. ML, Cin. Quar. Jour. Sci., II, 128, fig. 14. 



0. farperi, S. A. M. , [bid., II. [28. J. C. S. N. H., IV. 319. PI. 



8, figs. 6, ba. 



Shell medium size or large, gradually tapering ; septa arched, distant 

 from one-fifth to two-ninths the diameter of the shell : siphutuk sithccntral 

 or eccentric, varyingin position and in size; outer shell unknown. 

 Locality: Cincinnati and Warren and Clinton Counties. () 

 The numerous synonyms under this species show its variability. The 

 supposed species differ in what may be- considered individual variations, 

 or those produced by age. It is impossible to distinguish them by either 

 the descriptions or the figures, they are all so much alike. It has been 

 claimed that the 0. fosteri is the same as O. duseri. but no mention is 

 made in the description of the former of the most charac teristic feature of 

 the latter, viz., the interrupted line along one side of the shell. 



3. (). MOHRI, S. A. Miller. 1875. 

 (Cin. Quar. Jour. Sci.. II. 124. fig. 10.) 

 Shell elongated, tapering regularly, .16 of an inch to an inch: septa 

 rather strongly arched, distant one-fourth the diameter of the shell : siph- 

 nnde central, with appearance of a connected series of oval beads : 

 greatest diameter of siphuncle about one-fourth the diameter of the shell. 

 Outer chamber one-fourth the length of shell ; surface smooth, septa not 

 being shown. 



Locality: Versailles. Indiana. 



The species is best recognized by the smooth surface. It does not 

 seem to have been found immediately about Cincinnati. 



4. O. junceum, Hall. 1847. 

 (Pal. N. Y. I, 204. PL 47, 3 «-/) 

 Slender, terete, cylindrical, gradually tapering : septa thin ; siphuncle 

 small, central; section circular; surface finely striated transversely. 



