90 



MOLLUSCA. 



Shell smooth, nearly hemispherical; body large; spire pretty 

 large, produced, consisting of four rather inflated volutions, ter- 

 minating in a sharp apex ; a few indistinct lines of growth. 



Found in the Oolite called the White Nab, at Cloughton, 

 and in the Inferior Oolite Sand called the Blue Wick. 



11. Natica ELLiPTicA. — The Elliptical Natica, pi. XLIII. 



fig. 34. 



Natica elliptica. Phillips, II. p. 224, pi. 14, fig. 23. 



Shell elliptical ; body very large, covered with fine, oblique 

 stri.-c ; spire short, very small, consisting of three greatly de- 

 pressed volutions, with the apicial one quite obtuse ; columella 

 plain, and arcuated. 



Found in the Mountain Limestone, in Northumberland, and 

 at BoUand. 



12. Natica planispira The Flat-spired Natica, pi. 



XLIII. fig. 35. 



Natica planispira. Phillips, II. p. 224, pi. 14, fig. 30. 



Shell oblong-ovate ; body very large ; spire very small, con- 

 sisting of two well defined volutions, flattened above ; aperture 

 large, wide, and subquadrate; outer lip much expanded, and 

 produced in the centre ; columellar lip widely thickened above, 

 and narrowing as it descends; umbilicus closed; body flattened 

 above, and plicistriate. 



Found in the Mountain Limestone at BoUand. 



13. Natica hemiclausa — The Half-closed Natica, pi. 

 XLIII. fig. 36, 37. 



Natica hemiclausa. Sowerby, V. p. 125, pi. 479, fig- 2. 

 Fleming, p. 321. 



Shell smooth, subovate ; body very large in proportion to the 

 size of the spire, which consists of two very small, ill defined 

 volutions; aperture ovate, occupying about two-thirds of the 

 length of the shell; outer lip smooth-edged; pillar lip consider- 

 ably thickened above, narrow beneath, and slightly reflected 

 into the moderately-sized umbilicus, which it half closes ; it is 

 destitute of a spiral ridge ; the shell is thickened in the middle, 

 and gradually tapers towards the apex, and also towards the 

 base, which is somewhat produced. 



Found in the Crag at Woodbridge, Bramerton, Ipswich, and 

 various other places in Suffolk and Norfolk. 



14. Natica lirata — The Lyre-shaped Natica, pi. XLIII. 

 fig. 38, 39. 



Natica lirata. Phillips, IL p. 224, pi. 14, fig. 22. 



Shell suborbicular ; body very large ; spire very small, mam- 

 millary, consisting of two or three volutions, the lower one large 

 in proportion to the others, and terminating in a rounded apex; 

 aperture smooth internally, rather large ; outer lip greatly ex- 

 panded; body somewhat flattened above, and the whole surface 

 covered with longitudinal, lamellar, raised, thread-like stria;, 

 resembling the strings of a lyre. 



A variety is found with interlaminar striae. 



This species occurs in the Mountain Limestone at Bolland. 



15. Natica tabulata. — The Tabulated Natica, pi. XLIII. 

 fig. 40. 



Natica tabulata. Phillips, II. p. 225, pi. 14, fig. 29. 



Shell oblong-ovate; spire produced, consisting of three volu- 

 tions, flattened, or tabulated above ; body subcyhndrical, with a 

 subacute base ; and its superior portion flattened, and slightly 

 obUque, with five longitudinal striae. 



Found in the Mountain Limestone at Bolland. 



Natica. 

 pi. 



16. Natica ttjmidula. — The Slightly-tumid Natica, 

 XLIII. fig. 42, 43. 



Natica tumidula. Phillips, I. p. 129, pi. 11, fig. 25. 



Shell smooth, nearly orbicular ; body large and tumid ; spire 

 exceedingly small, consisting of two very ill defined volutions, 

 which hardly rise above the body ; aperture very large, extend- 

 ing nearly the whole length of the shell ; outer Up sharp at the 

 edge ; pillar lip broadly reflected on the columeUa, slightly waved 

 on the side next the aperture, the other side considerably in- 

 dented above, with a large callus, which completely closes the 

 umbilicus. 



Found in the Blue Wick, by Mr. Bean, of Scarborough, and 

 has also been met with in the OoUte Sand, Somersetshire. 



1 7. Natica elongata. — The Elongated Natica, pi. XLIII. 

 fig. 44. 



Natica elongata. Phillips, II. p. 225, pi. 14, fig. 28. 



Shell oblong-ovate ; body large, oblique ; spire smaU, con- 

 sisting of two or three mammillated volutions ; surface covered 

 with oblique, minute striae. 



Found in the Mountain Limestone at Bolland. 



18. Natica variata. — The Variable Natica, pi. XLIII. 

 fig. 45, 46. 



Shell subovate, slightly flattened above ; spire small, consist- 

 ing of two volutions, with an acute apex ; surface covered with 

 stria;, which is partly oblique and partly spiral ; aperture sub- 

 oval; outer lip rather expanding; piUar lip broadly reflected on 

 the columella; umbilicus closed. 



Found in the Mountain Limestone at Bolland. 



19. Natica striata. — The Striated Natica, pi. XLIII. 

 fig. 47, 48. 



Natica striata. Sowerby, IV. p. 99, pi. 373, two upper 

 figures. Fleming, p. 321. 



Shell smooth, oblong-ovate ; spire smaU, consisting of three 

 narrow, but weU defined volutions, the apicial one somewhat 

 obtuse ; aperture, occupying about three-fourths of the length 

 of the shell, rounded below, and a little contracted above; outer 

 lip blunted at the edge; inner lip broadly reflected on the colu- 

 mella above, but with a sinus at the umbilical region; umbilicus 

 of medium size, open, and destitute of spiral ridges ; base con- 

 centrically striated. 



Found in the London Clay. 



20. Natica depressa. — The Depressed Natica, pi. XLIII. 

 fig. 49, 50. 



Natica depressa. Sowerby, I. p. 21, pi. 5, lower figures. 

 Fleming, p. 320. 



SheU slightly ovate ; spire of medium length, consisting of 

 five weU defined and rounded volutions, their superior surface 

 subtabulated ; body volution subcompressed above the centre, 

 the top being flattened; aperture slightly ovate, rounded 

 below, and slightly contracted above ; inner lip rather broadly 

 reflected on the columella, and of nearly uniform breadth 

 its whole length ; umbilicus rather small, oblong, and rather 

 shallow. 



Found in the Crag Marl at Woodbridge, Suffolk. 



21. Natica canalicolata The Canaled Natica, pi. 



XXXIII.* fig. 19, 20. 



Natica canaliculata. Sowerby, Geo. Trans. IV. 2nd series, 

 p. 336, pi. 11, fig. 12, and pi. 18, fig. 6. Ampullaria canalicu- 

 lata, ManteU, Geo. of Sussex, p. 87, pi- 19, fig. 13. 



