BULINUS. 



MOLLUSCA, 



99 



apex; aperture elongated, narrow, acutely pointed above; outer number of its volutions, which for the most part are few; 



aperture oval, wide, anteriorly rounded; outer lip simple, 

 reflected, continuous, joining the columellar lip without 

 an emargination, and reflected over part of the body ; 

 columella smooth, straight, without a truncature, or 

 widening at the base. 



1. BuLiNUs cosTELLATUs The Ribbed Bulinus, pi. 



XL VI. fig. 30, 31. 



Bulinus costellatus. Sowerby, IV. p. 89, pi. 366. Fleming, 

 p. 266. 



Oblong-ovate, slightly inflated; spire with four nearly flat- 

 sided volutions, the apex rather obtuse ; aperture elongated, 

 acute above, and rounded below, occupying about half the 

 length of the shell; surface covered with numerous, small, thin, 

 sharp, longitudinal, slightly oblique ribs, the interstices plain. 



Fresh Water formation. Isle of VViuht. 



This species differs from the following, hut the aperture in this is much 

 larger in proportion to the size of the shell, and, besides, it is always a 

 dextral shell, while all the specimens of B. ellipticus are sinistral. 



2. Bulinus ellipticus The Elliptical Bulinus, pi. 



XLVI. fig. 36, 37. 



Bulinus ellipticus. Sowerby, IV. p. 46, pi. 337- Fleming, 

 p. 266. 



Shell an elongated ellipsis, thickened in the centre, and gra- 

 dually tapering to both extremities ; body occupying about half 

 the length of the shell ; spire with five reversed, very slightly 

 inflated volutions, with an obtuse apex, and the sutural line 

 shallow; aperture small, narrow, its length being equal to twice 

 its width, situate on the left side, contracted above, and wide 

 below; columella a little oblique; outer lip plane; base equally 

 blunt with the apex; whole surface covered by numerous, some- 

 what obtuse, longitudinal, slightly oblique ribs, with furrows 

 between them. Sometimes attains the size of four inches. 



Fresh Water formation at Schalcomb, Isle of Wight. 



lip much thickened and elevated in front, and distinctly defined 

 behind ; inner lip with a broad reflection, and three strong, 

 sharp plaits, the upper one partly concealed by the callous, the 

 lower one formed by the spiral edge of the columella; base 

 slightly notched. Length upwards of three-eights of an inch. 

 The Crag at Ramshot. 



8. Auricula simulata. — The Dissembled Auricula, pi. 

 XLVLfig. 40, 41. 



Auricula siimilata. Sowerby, II. p. 144, pi. 163, fig. 5, 6. 

 Bulla simulata, Brander, p. 61. 



Oblong-ovate ; spire of medium length, consisting of four 

 ventricose, well defined volutions; aperture elongated, narrowed 

 both above and below ; outer hp sharp, even on the edge, not 

 much expanded, and striated internally ; columellar lip slightly 

 thickened, and provided with two broad, prominent, laterally 

 compressed plaits, and a slight sinus dividing this from the 

 outer lip ; whole surface covered by spiral, close-set ribs, ser- 

 rated on both sides, facing each other on the opposed ribs, and 

 forming a series of cell-hke hollows. Length three-quarters of 

 an inch. 



The London Clay, Barton Cliff. 



9. Auricula discrepans. — The Discrepant Auricula, pi. 

 XLVI. fig. 42, 43. 



Auricula simulata. Sowerby, II, p. 144, pi. 163, fig. 7, 8. 



Oblong-ovate ; spire conical, of medium length, with five 

 slightly ventricose volutions, ending in an acute apex ; aperture 

 oblong, contracted and pointed above, as well as below ; outer 

 lip plain and sharp at the edge, and internally striated ; pillar 

 lip broadly reflected on the columella, with three rather oblique 

 plaits, the superior one shorter and more slender than the 

 others ; surface covered with spiral, close-set, serrated ribs, the 

 points of each nearly joining with those of the opposing ribs, 

 leaving cell-like openings between them. 



London Clay at Barton Cliff and Hordwell. 



This shell may easily be mistaken for A. simulata, but differs in being 

 somewhat more elongated, the spire less ventricose and more acute, in 

 having an additional volution, and in the plaits of the lip being more ob- 

 lique, with a third and smaller one above the others. 



10. Auricula inflata The Inflated Auricula, pi. 



XXX.* fig. 30. 



Auricula injlata. Sowerby, Geo. Trans. IV. N. series, p. 

 336, pi. 1 1, fig. 1 1. Bennett, Cat. Wilt. Foss. p. 2. 



Oblong-ovate ; body long ; spire short, with four rather in- 

 flated volutions, the apicial one acute; aperture subquadrangular 

 below, but with one of its upper angles acutely elongated ; outer 

 lip much thickened, obtuse on the edge, and united with the 

 inner lip, which has two strong plaits, the upper one slightly 

 inclined downwards at the point, the lower one sometimes 

 divided in the middle by a longitudinal groove ; surface with 

 numerous spiral lines of elongated punctures. 



This species differs from A. incrassata, in being much longer, with the 

 lip less enlarged. 



Found in the Gault, Kent and Wiltshire. 



Genus LV.— BULINUS.— .BrM<7M?eVe. 

 Shell oval or oblong, generally thin, and covered with 

 a slender epidermis ; spire obtuse, variable in length and 258. 



Genus LVl.—COCRLlCARl'i^ A.— Brown. 



Shell subdiscoidal ; spire variable, subdepressed in 

 some, and more subconic in others ; body provided with 

 a carina on its upper edge; base imperforate, and ven- 

 tricose ; aperture subquadrangular ; columella with a 

 broad, thickened callus. 



1. CocHLiCARlNA EXPANSA. — The Expanded Cochlicarina, 

 pi. XLVIL fig. 1, 2. 



Helicina expansa. Sowerby, III. p. 129, ph 273, fig. 1, 2, 

 3. Fleming, p. 258. 



Suborbicular, nearly smooth ; body flattened above, with an 

 acute carina on its superior edge, which is continuous at the 

 base of the volutions to the apicial one; spire conical, depressed, 

 consisting of four flattened, abruptly diminishing volutions, end- 

 ing in an acute apex, and obscurely striated ; body very ventri- 

 cose below, with an expanded callus at the columella, spreading 

 over a considerable portion of the base. 



Blue Lias at Lyme Regis. 



2. Cochlicarina solarioides — The Sun-like Cochlica- 

 rina, pi. XL VII. fig. 3, 4. 



Helicina solarioides. Sowerby, III. p. 129. Fleming, p. 



