302 MOLLUSCA. PECTINIBRANCHIA. Tueeitella. 



212. P. decussata. — Whorls eight or nine, strongly striated 

 transversely ; minutely striated spirally. 



Helix dec. Mont. Test. Brit. 399. t. xv. f. 1 — On the shore at Wey- 

 mouth, Mr Bryer. 

 Length /jjths of an inch ; breadth I 1 5 th ; white, slender ; whorls nearly 

 flat, the separating line extremely fine ; aperture narrow, suboval, contract- 

 ed at both ends ; outer-lip somewhat expanded, and a little thickened at the 

 back ; inner lip slightly replicated. 



213. P. pallida. — Whorls six or seven, smooth ; outer-lip 

 arcuated. 



Turbo pal. Mont. Test. Brit. 325. t. xxi. f. 4 — In sand, Salcomb Bay. 



Length |th of an inch ; breadth §ds less ; slender, tapering to a fine point ; 

 whorls separated by a well-defined line ; aperture suborbicular, a faint du- 

 plicature on the pillar-lip, forming behind a small cavity. 



In the Mineral Conchology, the following fossil shells are referred to the 

 genus, though it is more probable that they belong to Limnea or Paludina. 



1. P. orbicularis Conical, acute, smooth ; whorls about six, ventricose ; 



aperture nearly round. — Sower. Min. Conch, t. clxxv. f. 1.— Freshwater Lime- 

 stone, Shalcomb, Isle of Wight. 



2. P. angulosa. — Conical, smooth ; whorls subcarinated ; aperture nearly 

 round Sower. Min. Conch, t. clxxv. f. 2. — Along with the last. 



3. P. minuta. — Elongated, smooth ; whorls five or six ; obscurely squared ; 

 aperture oblong. — Sower. Min. Conch, t. clxxv. f. 3 — Along with the last. 



Gen. XLIX. TURRITELLA— Shell elongated ; the whorls 

 numerous, produced ; aperture wide ; the pillar-lip slightly 

 rounded. 



214. T. terebra. — Whorls about sixteen, with numerous spi- 

 ral ridges. 



Buccinum tenue, List. An. Ang. 161. Conch, t. nxci. f. 57. Turbo Ter. 



Linn. S. Syst. i. 1239. Penn. Brit. Zool. iv. 130. t. Lxxxi. f. 1 13. Mont. 



Test. Brit. 293 — Common. 

 Length sometimes exceeding two inches ; breadth of the body-whorl half 

 an inch, of a reddish or purplish brown ; whorls sometimes eighteen in num- 

 ber, ending in a fine point ; the larger whoi-ls rounded, with five or six pro- 

 minent ridges, besides smaller ones, crossed by the layers of growth. In the 

 young shells the ridges are less numerous, and the anteal edge of the body- 

 whorl is flattened. The aperture, in young shells, is subquadrangular ; in an 

 old specimen the outer lip is round and thin, and the pillar-lip nearly straight. 

 The animal is yellow, striped with dusky, with the tentacula short. — This 

 species resides in deep water, but is frequently thrown ashore after storms- 



215. T. exoleta. — Whorls about twelve, spirally striated, with 



two broad rounded spiral ridges. 



Cochlea variegata, List. Conch, t. Dxci. f. 58. — Turbo exol. Linn. Syst. i. 



1239 Turbo cinctus, Don. Brit. Shells, t. xxii. f. 1. Mont. Test. 



Brit. 295. — On the English coast, rare. 



