94 CLASS III. GASTEROPODA. ORDER VI. PULMOBRANCHIATA. 
The shell of Truncatella, of which we give magnified views, may be de- 
scribed as being turriculated, cylindrical, and either decollated or obtusely 
truncated at the apex ; the whorls are smooth, or transversely ribbed, and 
the aperture is oval, the peritreme or margin being continuous, and the 
lip simple. The operculum is oval, and somewhat spiral. 
Examples. 
Pl. CLXXXII. Fig. 1. 
TruncaTeLLa Montacuti, Lowe, Zool. Journ., vol. v. p. 303. 
Turbo subtruncatus ? Montague. 
Pl. CLXXXII. Fig. 2. 
TRUNCATELLA VENTRICOSA, Sowerby MSS. 
PL CLXXMIL, Hie 2: 
TRUNCATELLA CLATHRUS, Lowe, Zool. Journ., vol. v. p. 303. 
Pl. CLXXXIL. Fig. 4. 
TRUNCATELLA stRiATA, Sowerby (J. D.C.), Philosophical Magazine. 
Pl. CLXXXII. Fig. 5. 
TRUNCATELLA TRUNCATULA (var. a.). Lowe, Zool. Journ., vol. v. p. 303. 
Deshayes, Note in Edition of Lamarck, vol. viii. p. 365. 
Helix subcylindrica, Montague. 
Cyclostoma truncatulum, Draparnaud. 
Paludina truncata, Payrandeau. 
Rissoa truncata, Philippi. 
Truncatella levigata, Risso. 
Pl. CLXXXII. Fig. 6. 
TRUNCATELLA SCALARIFORMIS, Nobis, Proceedings Zool. Soc., 1842. 
Pl. CLXXXII. Fig. 7. 
TRUNCATELLA CaRIB£ENSIS, Sowerby MSS. 
