GASTEROPODA. 29 



2. Nassa incrassata. Mull. Tab. Ill, fig. 4. 



Tritonium incrassatum. Mull. Prod. No. 294fi, 1773. 

 Buccinum macula. Mont. Test. Brit. p. 241, t. 8, fig. 4, 1803. 



— Ascanias. Brug. ex Phil. En. Moll. Sic. vol. ii, p. 188. 



— asperulum. Broc. t. 5, fig. 8, 1814. 

 Nasa incrassata. Flem. Brit. An. p. 340, 1828. 

 Nassa incrassata. 5. Wood. Catalogue 1842. 



N. Testa ovato-conicd, subturritd ; spird acuta; longitudinaliter costatd ; transversim 

 anguste striata; anfractibus 6 — 7 convexis, tumidis ; aperlurd subrotundd ; labro 

 incrassata, varicoso, intus denticulato. 



Shell rather small, ovate-conical, subturreted, longitudinally costated, and finely 

 striated transversely ; whorls 6 — 7 convex, tumid ; aperture subcircular, with a 

 thickened outer lip, denticulated within. 



Axis, \ of an inch, nearly. 



Locality. Cor. Crag, Sutton. 



Red Crag, Sutton. Recent, Britain. 



Very scarce in the lower formation ; more abundant in the Red Crag. My speci- 

 mens seldom exceed f of an inch in length. The costse in the last volution vary from 

 12 — 15, with 12 — 15 threads along the whorls, and carried over the ribs. Denti- 

 culations within the lip, lower one the most produced, with a distinct ridge on the 

 opposite side of the canal at the base of the columella, contracting the entrance to 

 the canal, with a prominent tooth upon the body whorl, near the upper part of the 

 aperture. This appears to correspond with the recent species in every character 

 except its size, the recent British specimens being generally larger. 



3. Nassa granulata. /. Sow. Tab. Ill, fig. 3. 



Buccinum granulatum. J. Sow. Min. Con. t. 110, fig. 4, 1815. 



Nyst. Coq. foss. de Beige, p. 575, pi. 43, fig. 11, 1844. 

 Nassa granulata. S. Wood. Catalogue 1842. 



N. Testa ovato-conicd, turritd, apice acuto ; anfractibus convexis, longitudinaliter 

 costatis, transversim striatis ; striis elevatis granulatis ; dperturd subrotundd; labro 

 incrassato intus dentato ; labio superne unidentato. 



Shell ovato-conical, with an elevated and acute spire ; whorls convex, longitudi- 

 nally costated, and decussated by coarse and elevated stria? ; aperture subcircular, 

 with a reflected left lip and thickened margin denticulated within. 



Axis, f of an inch. . 



Locality. Cor. Crag, Sutton. 

 Red Crag, passim. 



Very abundant in the Red Crag, but rare in the Coralline. In shape it much 

 resembles the preceding species, but the stria?, or rather ridges, are fewer and larger, 

 and carried over the costae, which give it a granulate appearance, and regularly 

 decussate the exterior. The outer lip has fewer teeth. The tooth on the body 



