86 



MOLLUSCA. 



Pleurotomaria. 



Shell somewhat depressed ; body large, iiiHated ; spire very 

 short, consisting of three volutions, terminating in a very acute 

 apex ; mesial band broad, plain, and investing the body some- 

 what below the centre; surface covered with fine, regular, spiral 

 striaB. 



Found in the Mountain Limestone, BoUand. 



I have altered the specific name, as it was too near striata, No. 12. 



6. p. SULCATA The Sulcated Pleurotomaria, pi. XL. 



fig- 7. 



Pleurotomaria sulcata. Phillips, Geo. of Yorkshire, II. p. 

 226, pi. 15, fig. 6. 



Shell ovoid ; body very large ; spire very small, consisting of 

 three rounded volutions, with an obscure, nearly central, trans- 

 verse mesial band ; surface invested with numerous, rounded, 

 spiral sulci. 



Found in the Mountain Limestone, BoUand. 



7. P. suLCATULA. — The Furrowed Pleurotomaria, pi. XL. 

 fig. 11. 



Pleurotomaria sulcatula. Phillips, Geo. of Yorkshire, IL 

 p. 226, pi. 15, fig. 5. 



Shell subdepressed ; body large ; spire small, conoidal, with 

 three slightly inflated, rapidly diminishing volutions, terminating 

 in a subacute apex ; aperture transversely oblong, much ex- 

 panded ; superior surface spirally furrowed ; inferior surface 

 with fine concentric striae ; mesial band rather narrow, and 

 situate a little below the centre. 



Found in the Mountain Limestone, BoUand, and the Isle of 

 Man. 



8. P. EXPANSA. — The Expanded Pleurotomaria, pi. XL. 

 fig. 8. 



Pleurotomaria e.vpanm. Phillips, Geo. of Yorkshire, IL p. 



226, pi. 15, fig. 4. 



Shell subconic, depressed; body very large; spire very small, 

 consisting of three depressed, gradually decreasing volutions; 

 aperture much expanded transversely ; mesial band flattened, 

 and crossed by arcuated striae ; surface covered with oblique 

 striae, and obsolete spiral stria?. 



Found in the Mountain Limestone, Bolland. 



9. P. LIRATA — The Ridged Pleurotomaria, pi. XL. fig. 

 9, 10. 



Pleurotomaria livata. Phillips, Geo. of Yorkshire, II. p. 



227, pi. 15, fig. 13. 



Shell conical; body large; spire small, consisting of four gra- 

 dually tapering volutions, terminating in an acute apex; aperture 

 nearly circular, slightly pointed above; outer lip plain; inner lip 

 narrowly reflected on the columella above, increasing in breadth 

 as it descends; mesial band prominent, with arcuated transverse 

 striae; surface above the band with longitudinal, oblique sulci, 

 and with straight, longitudinal furrows beneath the band ; base 

 rounded. 



Found in the Mountain Limestone, Bolland. 



10. P. ACUTA. — The Acute. Pleurotomaria, pi. XL. 

 fig. 12. 



Pleurotomaria acuta. Phillips, Geo. of Yorkshire, II. p. 



228, pi. 15, fig. 21. 



Shell reversed, ^anical ; spire consisting of three inflated 

 volutions ; body traversed at its angle by a short mesial band ; 

 surface obliquely striated above the carina, and with spiral lines 

 below. 



Found in the Mountain Limestone, Bolland. 



11. P. ABDITA — The Concealed Pleurotomaria, pi. XL, 

 fig. 13, 14. 



Pleurotomaria dbdita. Phillips, Geo. of Yorkshire, IL p. 

 227, pi. 15, fig. 15. 



Shell smooth, subdepressed ; body very large ; spire very 

 small, consisting of three flat volutions, a little rounded at the 

 sides, ending in an obtuse apex; aperture large, transversely 

 expanded ; outer lip bounded by the band ; inner lip reflected 

 on the columella; mesial band broad, flat, and losing itself in 

 the suture of the spire. 



Found in the Mountain Limestone, Bolland. 



12. P. STRIATA. — The Striated Pleurotomaria, pi. XL. fig. 

 15, 16. 



Helix? sfriatus. Sowerby, Min. Conch. II. p. 159, pi- 171, 

 fig. 1. 



SheU conical, subdepressed; body large; spire small, consist- 

 ing of three flattened volutions, rounded at the sides; aperture 

 suborbicular, occupying more than half the length of the body ; 

 an elevated, broad, transverse, me.'iial band invests the centre of 

 the body, and is continued along the base of the volutions of 

 the spire, and crossed by arcuated striae; columella soHd; sur- 

 face covered by oblique, somewhat wide stria>. 



Found in the Mountain Limestone of Derbyshire. 



13. P. GLABRATA The Smooth Pleurotomaria, pi. XL. 



fig. 17. 



Pleurotomaria glabrata. Phillips, Geo. of Yorkshire, II. p. 

 229, pi. 15, fig. 28. 



Shell depressed, smooth; body large; spire small, with three 

 gradually tapering volutions; body rounded at the sides; length 

 only about half its diameter; destitute of a band. 



Found in the Mountain Limestone, Bolland. 



14. P. FLAMMIGERA — The Flame Pleurotomaria, pi. XL. 

 fig. 18. 



Pleurotomaria Jiammigera. Phillips, Geo. of Yorkshire, 

 II. p. 226, pi. 15, fig. 2. lb.. Treatise on Geology, I. p. 163, 

 fig. 11. 



SheU subconic; spire with three moderately inflated volu- 

 tions; body having a broad mesial band, with arcuated trans- 

 verse stria} ; whole surface covered witli longitudinal and 

 transverse, wide-set stria;, producing a fine reticulated appear- 

 ance ; above the band, the surface is covered with handsome 

 flame-like, zigzag lines of colour. 



Found in the Mountain Limestone, Bolland. 



15. P. ovoiDEA. — The Ovate Pleurotomaria, pi. XL. fig. 



19- 



Pleurotomaria ovo'idea. Phillips, Geo. of Yorkshire, II. p. 

 228, pi. 15, fig. 27. 



Shell smooth, ovate, subconic; body large; spire small, con- 

 sisting of four moderately rounded volutions, subangular below; 

 surface with flexous lines of growth. 



Found in the Mountain Limestone, in Derbyshire, Bolland, 

 Isle of Man, and Otterburn, Northumberland. 



16. P. Helicoides. — The Helix-formed Pleurotomaria, 

 pi. XL. fig. 20. 



Pleurotomaria Helicoides. Phillips, Geo. of Yorkshire, II. 

 p. 228, pi. 15, fig. 26. 



Shell smooth, subdepressed ; body large ; spire small, with 

 four rounded volutions, terminating in an acute apex ; base 



