FAUKA OP ORTHAULAX PUGNAX ZONE. 89 



BITTIUM (PRISCUM van?) SORA, new variety. 



A shell which may be a variety of B. priscum and is only repre- 

 sented by a single specimen has been received too late for figuring. 

 It has 11 whorls and an acute apex; the whorls in front of the suture 

 are excavated and plain; at the periphery there is one strong spiral 

 thread separated by an interval from two closely adjacent threads in 

 front of it, and in the later whorls a still stronger thread just behind 

 the suture and on the last whorl marginating the base; the base is 

 flattish, with four or five fine spiral threads, and the canal obso- 

 lete. The axial sculpture is of numerous obscure riblets which 

 slightly undulate the spirals. Height 8.75 ; of last whorl 3.5 ; maxi- 

 mum diameter 3.0 mm. 



Tampa silex beds, collected by E. J. Post, U. S. Nat. Mus., No. 

 214740. 



BITTIUM ADELA, new species. 



Plate 13, fig. 16. 



Shell small, thin, with 8 rather rapidly increasing whorls; spire 

 conic, apex acute; suture distinct, not channeled; axial sculpture of 

 (on the penultimate whorl eleven) short nodular ribs, conspicuous 

 on the periphery, obsolete toward the sutures; behind the periphery 

 the whorl slopes flatly toward the preceding suture, the anterior 

 slope is much shorter and terminates at a carina in front of which 

 the next suture is laid ; on this slope there is spiral sculpture of four 

 or more fine close-set revolving threads; the posterior slope is simi- 

 larly sculptured, and on the periphery there are indications of a 

 slightly stronger but similar single thread; the sculpture is essen- 

 tially the same over the whole spire ; base of the shell limited by the 

 post sutural carina before mentioned ; flattish, sculptured with about 

 nine revolving little elevated threads, with slightly wider inter- 

 spaces; canal short, distinct; outer lip thin, defective, not inter- 

 nally Urate; aperture subquadrate. Length 8.5, maximum diameter 

 4.5 mm. 



Tampa silex beds. Ballast Point, Tampa Bay, Florida. One speci- 

 men, possibly immature, from the Post collection, U. S. Nat. Mus. 

 No. 165104. 



Genus CERITHIUM Brugui^re. 



Cerithium (part) Brugui£:ee, Encycl. Meth., pt. 2, 1792, p. 467. — Lamabck, 



Prodrome, 1799, p. 73. Type, Murex aluco Linnaeus. 

 Pseudovertagus Vignal, Bull. Mus. Nat. Hist. Paris, p. 358, 1904. 



CERITHIUM GEORGIANUM Lyell and Sowerby. 



Cerithium georgianum Lyell and Sowerby, Quart. Journ. Geol. Soc. Lon- 

 don, vol. 1, p. 439, fig. — , 1845. — Dall., Trans. Wagner Inst., vol. 3, pt. 

 2, p. 278, 1892. 

 Tampa silex beds Ballast Point, Tampa Bay, Florida ; also in the 

 rock dredged from the ship channel off the point, and from the Oli- 



