94 



MOLLUSCA. 



Paludina. 



2. Palcdina LENTA. — Tlie Flimsy Paludina, pi. XLV. 

 fig. 2, 3, and 9. 



Paludina lenta. Fleming, p. 316. Vuipara lenta, Sowerby, 

 I. p. 79, pi. 31, fig. 3. HelLc lenta, Brander, fig. 60. 



Oblong-ovate, smooth; spire consisting of four inflated, 

 deeply divided volution's ending in an acute apex ; aperture 

 nearly orbicular, entire, slightly contracted above, and rounded 

 below ; surface sometimes exhibiting distinct lines of growth. 

 Length an inch ; breadth not half an inch. 



Found in the London Clay at Barton Cliff and Hordwell. 



3. Paludina Extensa. — The Long Paludina, pi. XLV. 

 fig. 4. 5. 



Paludina extensa. Fleming, p. 316. Sowerby, L p. 78, pl- 

 31, fig. 2. 



Smooth, oblong-ovate; body inflated; spire consisting of four 

 somewhat ventricose volutions, a little angular below ; aperture 

 nearly orbicular, a little contracted above ; outer lip somewhat 

 extended; inner lip slightly reflected over the columella, with a 

 small, narrow- umbilicus behind it. 



Found in the London Clay at Blackdown, Hordwell, and 

 Barton. 



4. Paludina subopebta. — The Half-covered Paludina, 

 pi. XLV. fig. 7, 8. 



Paludina suboperta. Fleming, p. 316. Vivipara svhoperta. 

 Sowerby, L p. 80, pi. 31, fig. 6. 



Convex, smooth ; spire with four inflated volutions, with a 

 flattened line on their superior portion, and terminating in an 

 acute apex ; aperture ovate, contracted above ; inner lip a little 

 reflected on the columella. 



Found in the Crag at Holywells. 



5. Paludina fluviobum. — The Fresh Water Paludina, pi. 

 XLV. fig. 12, 13. 



Paludina jluviorutn. Fleming, p. 316. Vivipara Jluvio- 

 rum, Sowerby, L p. 79, pi. 31, fig. 1. Mantcll, Geo. of 

 Sussex, p. 4a, pi. 17, fig. 56. Fitton, Geo. Trans. IV. 2nd 

 series, p. 363. 



Ventricose, smooth; spire with four or five inflated volutions, 

 well defined by the sutural line, and terminating in an acute 

 apex ; lines of growth sharp, nearly equidistant, and having the 

 appearance of fine striae. 



Found in the Weald Clay, above and below the Iron Sand, 

 Sussex and Isle of Wight. 



6. Paludina cabinifeba The Keeled Paludina, pi. 



XLV. fig. 10, 11. 



Paludina carinifera. Sowerby, VI. p. 12, pi. 509, fig. 3, 

 Fleming, p. 316. Fitton, Geo. Trans. IV. 2nd series, p. 363. 



Elongated, smooth, convex ; spire with three or four volu- 

 tions, ending in a blunted apex, the two superior volutions 

 encompassed with a linear keel at their lower edge ; aperture 

 slightly ovate, a little contracted above. 



Found in the Purbcck Limestone and Hastings Sand, Sussex. 



7. Paludina elongata. — The Lengthened Paludina, pi. 

 XLV. fig. 14, 15. 



Paludina elongata. Sowerby, VI. p. 11, pi. .^09, fig. 1, 2. 

 Fleming, p. 316. Fitton, Geo. Trans. IV. 2nd scries, p. 363. 



Considerably elongated, smooth ; body and spire of nearly 

 equal length ; the latter with four not much inflated, but well 

 defined, rather oblique volutions, with a sharp apex ; aperture 

 oblong, somewhat contracted above. 



Found in the Weald Clay at Compton Grange, Chive, Isle of 

 Wight ; East Peckham, Kent ; and Sussex. 



8. Paludina Sussexensis — Tlic Sussex Paludina, pi. 

 XXXIII.* fig. 18. 



Paludina Sussexensit. Sowerby, Zool. Trans. IV. N. series, 

 p. 346, pi. 22, fig. 6. 



Elongated, smooth ; spire acute, consisting of four flat-sided 

 volutions. 



Found in the Hastings Sand, Sussex. 



FAMILY VII._MELANIDES. 



Fluviatile shells, with the margin of the aperture 

 disunited, the outer lip edged; animal furnished with 

 two tentacula. 



Genus XLIX—MELAtiOPSlS—Firussac. 



Shell oblong, fusiform, or conico-cyliiulrical ; spire 

 with from five to fifteen volutions, terminating in a 

 pointed apex, but decollated in some species ; body fre- 

 quently equal to two-thirds of the whole shell ; aperture 

 oblong-ovate, pointed at the iii)pcr extremity ; outer 

 lip somewhat thickened, slightly inflected, and deeply 

 notched above; columella twisted, solid, callous, and 

 separated from the exterior margin at the base, by a 

 deep sinus, in most species, but devoid of it in some ; 

 callosity thickest at its junction with the upper extremity 

 of the aperture ; operculum spiral, corneous, and not 

 quite fitting the aperture. 



1. Melanopsis bbevis. — The Short Melanopsis, pi. XLV. 

 fig. 24, 25. 



Melanopsis brevis. Sowerby, VI. pi. 523, fig. 2. Fleming, 

 p. 3.';9. 



Ovate ; body large, inflated, smooth ; spire short, with three 

 well rounded volutions, a little contracted above; apex acute; 

 aperture oval, a little narrowed both above and below ; outer 

 lip plain; inner lip thickened, equal in breadth its whole length; 

 callus rather flat. Diameter about two-thirds of its length. 



Found in the Han)pshirc Fresh Water formation of Hord- 

 well. 



2. Melanopsis cabinata. — The Keeled Melanopsis, pi. 

 XLV. fig. 18, 19. 



Melanopsis carinata. Sowerby, VI. p. 41, pi. 503, fig. 1. 

 Fletning, p. '.iVj. 



Oblong-ovate, considerably acuminated, smooth ; body very 

 large; spire short, consisting of five volutions, with a spiral keel 

 winding along the up|ier edge of each, giving a lurrctcil aspect 

 to the spire; tip acute; body with flattened Hides, and an 

 obscure carina near its upper edge ; aperture elongated, a little 

 contracted both above and below ; outer lip thin, and jilain on 

 the edge; inner lip broadly rellccted upon the columella. 

 Length somewhat more than double its diameter. 



