Ampullama. MOLLUSCA. PECTINIBRANCHIA. 317 



ture suborbicular ; right lip enlarged— Sower. Min. Conch, t. cclxxxiv. two 

 lower figures.— London Clay. 



4. A. ambulacrum Globose, with a canal round an acute spire ; pillar-ca- 

 vity plain within Sower. Min. Conch, t. ccclxxii. — London Clay. 



5. A. nobilis Subglobose, smooth ; spire conical, composed of a few con- 

 vex whorls; base very convex; no pillar cavity; aperture elliptical, sublu- 

 nate, pointed above.— Sower. Min. Conch, t. Dxxii. f. 1. — Carboniferous Lime- 

 stone. 



6. A. helicoidis. — Almost discoid, smooth ; spire very short, blunt ; whorls 

 nearly blended, round ; base with a pillar cavity ; aperture oblong. — Sower. 

 Min. Conch, t. Dxxii. f. 2. — Carboniferous Limestone, Ireland. 



7. A. canaliculata " Ventricose, whorls three or four ; transversely and 



obliquely striated ; the strife decussating each other ; spire short ; turns of 

 the spire separated by a deep channel." — ManU Geol. Suss. 87. t. xix. f. 13. 

 Blue Chalk Marl. — Mr Mantell likewise refers another shell to this genus, 

 but with doubt, " a subglobose, ventricose, univalve," p. 111. t. xviii. f. 11. 



Gen. MELANIA. — Shell turrited; aperture oblong; pillar- 

 lip smooth, and bent in the middle. 



1. M. sulcata Spire more than five times the length of its diameter, with 



spiral striae ; a concave furrow between each whorl ; whorls fourteen — Sower. 

 Min, Conch, t. xxxix. middle figure — London Clay, Stubbington Cliffs. 



2. M. Heddingtonensis A shell about three times as long as the diameter ; 



whorls eight or more, the surface of each concave near the middle, with an 

 obtuse angled rising near the upper part.— Sower. Min. Conch, t. xxxix. right 

 and left hand figures.— Upper and Middle Oolite. 



3. M. striata Length two and a half times as long as the diameter ; whorls 



six or more, with about sixteen rounded spiral ribs, nearly equal on the outer 

 part of the whorls, but widened on the concealed parts — Sower. Min. Conch, 

 t. xlvii. — Lias. 



4. M. lineata Acuminated ; whorls nine, finely striated across ; aperture 



angular above — Sower. Min. Conch, t. ccxviii. f. 1.— Inferior Oolite, at Dun- 

 dry. 



5. M./asciafo.— Turrited, short; whorls six, spirally striated, marked with 

 three coloured bands, coronated; aperture ovate. — Sower. Min. Conch, t. 

 ecxli. f. 1. — Fresh-water Formation, Isle of Wight. 



6. M. costata.— Turrited, spirally striated, transversely ribbed ; mouth ob- 

 ovate. — Sower. Min. Conch, t. ccxli. f. 2 — London Clay, Hordwell. 



7. M. minima Turrited, smooth ; sides straight ; mouth ovate, pointed 



above ; base slightly produced — Sower. Min. Conch, t. ccxli. f. 3. — London 

 Clay, Brakenhurst, Hants. 



8. M. truncala Conical, elongated, smooth ; whorls angular below ; mouth 



ovate, acute above, truncated below. — Sower. Min. Conch, t. ccxli. f. 4. — Lon- 

 don Clay, Brakenhurst. 



With the exception of M. fasciata, it is doubtful if any of the preceding 

 species belong to the genus Melania. It is more probable that they are re- 

 lated to the marine Turbonidce. 



9. M. costellata.— Turrito-subulated spirally, with numerous longitudinal 

 ribs ; anteal lip with a canal in the inside. — Lam, Hist. Vert. vii. 543. {Bran* 

 der, Foss. Hant. f. 21-)— ManU Geol. 269. 



