FAUNA OF OKTHAULAX PUGNAX ZONE. 73 



rowly lunate, the outer lip slightly protractively arcuate, simple; 

 inner lip smooth; canal short, wide, slightly recurved; aperture ob- 

 structed by matrix, so that the existence of lirae on either lip is doubt- 

 ful. Height of shell 4.3, of last whorl &, maximum diameter 2 mm. 



Tampa silex beds at Ballast Point, Tampa Bay, Florida. 



Type-specimen from the Post collection, U. S. Nat. Mus. No. 

 165083. 



ASTYRIS ACANTHODES, new species. 

 Plate 4, fig. 4. 



Shell small, acute, of about 6 whorls regularly increasing; suture 

 distinct; surface smooth except for 4 or 5 minute spiral grooves 

 on the canal; whorls not inflated; outer lip thickened with 6 or 7 

 low denticles internally; body and pillar with a smooth, thin layer 

 of callus, canal very short and deeply notched. Height of shell 6, 

 of aperture 2, maximum diameter 2.5 mm. 



Tampa silex beds at Ballast Point, Tampa Bay, Florida; one 

 specimen. U. S. Nat. Mus. No. 166100. 



This little shell is almost identical with one which we have with- 

 out a name in the collection of the United States National Museum 

 from the Natural Well, Duplin County, North Carolina, of Mio- 

 cene age. 



Family MUEICIDAE. 



Genus MUREX (Linnaeus) Bolten. 



Murex Linnaeus, Syst., Nat., ed. 10, p. 746, 175S. First species, M. haus- 

 telltmi Linnaeus.— Bolten, Mus. Boltenianum, p. 144, 1798. First spe- 

 cies, M. hausteUimi Linnaeus. 



All Bolten's species of Murex belong to the group as commonly 

 restricted. 



Subgenus MUREX sensu strictu. 



Type. — Murex haustellum Linnaeus. 



MUREX MISSISSIPPIENSIS Conrad. 



Plate 5, fig. 10. 



Murex mississippiensis Conrad, Journ. Acad. Nat. Sci. Phila., series 2. 

 vol. 1, p. 116, pi. 11, fig. 30, 1848.— Dall, Trans. Wagner Inst., vol. 3, 

 pt. 1, p. 139, 1890. 

 Murex tritonopsis Heilpein, Trans. Wagner Inst., vol. 1, p. 107, pi. 15, fig. 

 39, 1887. 

 Oligocene of Vicksburg, Mississippi, Conrad; of the Tampa silex 

 beds, Heilprin and Dall ; and of the Chipola marls near the county 

 bridge over the Chipola river, formerly Bailey's Ferry, Florida, 

 Dall. U. S. Nat. Mus. No. 166102 and 168085. 



