74 



MOLLUSCA 



Manchester Turbo, pi 



LiTTORINA. 



16. T. Mancuniensis. — The 

 XXXVII.* fig. 15, 16. 



Turbo Mancuniensis. Brown, Transactions of the Manches- 

 ter Geological Society, I. p. 63, pi. 6, fig. 1, 2. 



Shell ovate; body large; spire short, consisting of three 

 ventricose volutions, separated by a channelled suture ; body 

 provided with many prominent, spiral ribs ; three on the body 

 above, with five or six concentric ones beneath on the base, and 

 two on each of the volutions of the spire: these are crossed 

 by numerous longitudinal wrinkles; aperture large, orbicular; 

 outer lip expanded, smooth; pillar lip with an oblong umbilicus 

 behind it. Length upwards of a quarter of an inch; body 

 nearly the same in diameter. 



Found in the Red Magnesian Marl at Collyhurst, Manchester, 

 by E. W. Binney, Esq., and is in the museum of the Manches- 

 ter Geological Society. 



17. T. MiNUTUS The Minute Turbo, pi. XXXVII.* fig. 



17, 18. 



Turbo minutus. Brown, Trans. Manchester Geo. Soc. I. p. 

 63, pi. 6, fig. 4, 5. 



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

 sistint' of three abruptly diminishing volutions, flattened above, 

 terminating in an obtuse apex, and separated by a somewhat 

 grooved suture ; aperture orbicular ; outer lip slightly notched 

 on the edge, produced by the projecting ribs; whole shell 

 covered with strong, slightly undulous transverse costse, two on 

 the superior portion of the body, the lower one so much larger 

 than the others, that it produces a carinated appearance, and 

 with four or five concentric ribs below on the base, v»hich is 

 flattened ; pillar lip with an umbilicus behind. 



Found in the Red Magnesian Marl at Collyhurst, Manchester, 

 by E. W. Binney, Esq., and is in the Manchester Geological 

 Society's museum. 



Genus XXXII.— LITTORINA.— PerMssac. 



Shell turbinated, generally ovate, or oblong-ovate, for 

 the most part thick and solid ; spire in general gradually 

 acuminated and subturreted, in some species very short 

 and obtuse at the apex; aperture round, or slightly ellip- 

 tical, somewhat acute above in some species ; outer lip, 

 or peritrenie, sharp-edged; columella somewhat flattened; 

 operculum horny, spiral, consisting of a few rapidly en- 

 larging volutions, and furnished with a central nucleus. 



1. L. Bartonensis The Barton Littorina, pi. XXXVIII. 



fig. 54, 55. 



Turbo Uttoreus. Sowerby, Min. Conch. I. p. 163, pi. 71, 

 fig. 1, two upper figures. 



Shell oblong-ovate, thick; body large; spire small, consisting 

 of three moderately inflated, well defined volutions, with their 

 upper parts nearly flat, terminating in an obtuse apex ; whole 

 surface covered with fine spiral, somewhat irregular strife; aper- 

 ture subovate, rounded beneath, and slightly contracted above ; 

 outer hp even at the edge, considerably thickened within ; pillar 

 lip broadly reflected on the columella. 



This shell differs from the L. communis in being much more erect, 

 in the volutions being much flatter on the sides, and in its obtuse 

 apex. 



Found in the Crag at Bramerton Hill, near Norwich. It is 

 often procured with the coloured bands quite distinct. 



2. L. COMMUNIS. — The Common Littorina, pi. XXXVIII. 

 fig. 56. 



Turbo Uttoreus. Sowerby, Min. Conch. I. p. 163, pi. 7J, 

 lower figure 1. 



Shell subovate ; body large ; spire short, acute, consisting of 

 three or four moderately inflated volutions, terminating in ari 

 acute apex; aperture suborbicular, slightly contracted above; 

 whole surface covered with numerous, slightly nodulous, but 

 regular striae. 



Found in the Crag at Bramerton Hill, near Norwich. 



3. L. RUDis. — The Robust Littorina, pi. XXXVIII. fig. 

 57, 58. 



Turbo rudis. Sowerby, Min. Conch. I. p. 164, pi. 71, fig. 2. 



Shell subovate; body occupying more than two-thirds of the 

 shell ; spire consisting of four moderately inflated and well 

 defined volutions, swelled above ; whole shell covered by 

 numerous spiral, somewhat irregular striae ; these are crossed 

 by a few inequidistant, longitudinal wrinkles, or lines of growth, 

 which gives the shell a rugged aspect. 



Found in the Crag, near Aldborough. 



4. L. PUNGENS. — The Pricking Littorina, pi. XXXVII.* 

 fig. 19. 



Littorina pungens. Sowerbj', Trans. Geo. Soc. IV. 2nd 

 series, p. 343, pi. 18, fig. 5. 



Shell conical, smooth ; body large, ventricose ; spire short, 

 consisting of five narrow, gradually tapering volutions, a little 

 flattened at the sides, and terminating in an acute apex ; aper- 

 ture orbicular, with an acute, angular elongation above ; outer 

 lip thin, and even. 



Found in the Lower Green Sand, Blackdown, by Dr. Fitton. 



5. L. GRACILIS. — The Slender Littorina, pi. XXXVII.* 

 fig. 20, 21. 



Littorina gracilis. Sowerby, Geo. Trans. IV. 2nd series, 

 p. 343, pi. 18, fig. 12. 



Shell elongated, acute ; body shorter than the spire, which 

 consists of five ventricose, deeply divided, and gradually taper- 

 ing volutions, terminating in a pointed apex; aperture round, 

 with a slight angle below ; outer lip even ; pillar lip slightl}' 

 reflected on the columella ; whole surface covered with wide, 

 longitudinal, regular furrows, which are crossed by transverse 

 spiral striae, giving it a fine decussated aspect. 



Found in the Lower Green Sand at Blackdown, by Dr. 

 Fitton. 



Genus XXXIII.— TROCHUS.—Z?ww«ms. 



Shell conical ; spire elevated, sometimes abbreviated ; 

 aperture more or less transversely depressed, frequently 

 quadrangular or trapeziform, its edge being oblique to 

 the direction of the last volution, exhibiting the inferior 

 portion of the columella; base generally flattish, or, in 

 some instances concave; columella more or less arcuated, 



