OiiTHOCERA. MOLLUSCA. CEPHALOPODA. 239 



** Striated transversely. 



10. O. striata — Nearly cylindrical, septa numerous, deep ; syphon nearly 

 central ; surface regularly striated transversely — Sower. Min. Conch, t. Iviii. 

 Flem. Wern. Mem. iii. 90 — Transitimi Limestone, Cork. In the clay -slate of 

 the same formation, at the Cove of Cork, another species occurs, the charac- 

 ters of which are not established. 



1 1. O. Steinhaueri — Tapering ; chambers deep, partitions distant, even 

 edged, circular ; syphon close to one side ; striae of the surface regular and 

 even. — Sower. Min. Conch. Ix. f. 4.— In Carboniferous Limestone. 



12. O. gigantea — Shell gradually tapering, finely striated, aperture up- 

 wards of 8 inches in diameter ; septa direct, numerous, deep ; syphon a small 

 distance from the centre — Sower. Min. Conch, t. ccxlvi. — In limestone of 

 the Old Red Sandstone, Dumfriesshire. 



*** Surface with transverse ridges. 



13. O. sulcata — Shell tapering ; ridges waved and striated ; syphon small, 

 central. The length of one specimen is 2 inches and i^oths, diameter at 

 the base /gths, and at the apex y^ths. It contains thirty-one ridges, which 

 are twice waved in going round the shell : both the ridges and intervening 

 grooves are finely striated. — Ure^s Ruth. 306, t. xvi. f. 2. Flem. An. Phil. v. 

 202, t. xxxi. 6. — In slate-clay of the Coal Formation. 



14. O. undata — Shell tapering, ridges waved and smooth ; pipe small, cen- 

 tral. In a specimen 1 inch and ,-oths in length, it is i'(,ths in diameter at 

 the base, and upwards of /gths at the apex ; with eleven ridges, more deep- 

 ly waved, and less numerous than the preceding. There is the appearance 

 of an epidermis of a black colour, and obscurely striated ; where the shell is 

 exposed, both the ridges and the grooves are perfectly smooth. An imper- 

 fect specimen of an Eschara adheres to the shell. — Flem. An. Phil. v. 203. 



In slate-clay of the Coal Formation. 



15. O. awnzi/am.— Subcylindrical ; ridges distant, nearly even and smooth. 

 The largest portion of the shell which I possess is about 1 inch in length, 

 and upwards of /gths in diameter ; ridges nearly tth distant ; more obtuse 

 than the preceding, with at least two chambers in the interval.— F/em. Ann. 

 Phil. V. 203.— In Carboniferous Limestone. 



16. O. annulata — Tapering, subcompressed, with strong, waved, slightly 

 oblique ridges, and intervening striae : syphon sublateral ; a space near the 

 aperture without ridges — Sower. Min. Con. t. cxxxiii. — Carboniferous Lime- 

 stone, Colebrookedale. 



17. O. rugosa — Subcylindrical ; ridges waved, and tuberculated with longi- 

 tudinal lines ; syphon minute, and placed close to the edge. The length of a 

 specimen which I possess is 1^ inch ; the diameter /gths ; the ridges are /gths 

 asunder, and contain two chambers m the interval — Flem. Ann. Phil. v. 203. 

 — In Carboniferous Limestone. 



**** With longitudinal planes or furrows. 



18. O. Gesneri — Conical, with numerous longitudinal furrows, regularly 

 concave and close.— Mart. Pet. Derb. t. 38. f. 1, 2. — In Carboniferous Lime- 

 stotte, Derbyshire. 



17. O. an^fw/am.- Nearly cylindrical, angular, with about 16 smooth Ion- 

 gitudinal planes ; syphon small and lateral. I jjossess about half an inch of 

 this shell, which is nearly of equal thickness, scarcely exceeding the tenth of 



an inch in diameter — Flem. Ann. Phil. v. 203. t. xv. f. 10 In Carboniferous 



Limestone. 



