438 MOLLUSCA. PSAMMOBIAM]. Psammobia. 



there are about twelve longitudinal ribs ; a slightly cloven tooth in one valve, 

 closing between two in the other, one of which is slightly cloven. 



492. P. fragilis. — Suboval, tumid, flexuous and produced 



at the posterior end, with transverse laminal stria?, and minute 



longitudinal ones. 



Tellina fragilis, Linn. Syst. i. 117- — T. jugosa, Brown, Wern. Mem. ii. 



506. t. xxiv. f. 2— P. fragilis, Turt. Biv. Brit. 88. t. vii. f. 11, 12 



Coast of Ireland. 



Length about an inch, breadth an inch and a half; brownish; very tumid 

 at the larger end, and sloping to a rough flexuous point at the other ; teeth 

 strong, elevated ; in one valve a cloven tooth, with a cavity on each side for 

 the reception of the two teeth of the opposite valve. 



493. P. Laskeyi. — Oval-oblong; slightly contracted retrally, 



with a few obsolete concentric ridges. 



Tellina Lask. Mont. Test. Brit. Sup. 28. t. xxviii. f. 3 — Frith of Forth, 

 Mr Laskey. 



Length half an inch, breadth three quarters ; purplish white, with an oval 

 cuticle ; beaks slightly prominent, retrally ; slightly obtuse; two approximate 

 subbifid teeth in one valve, and a single tooth in the other. 



— 494. P. Ferroensis. — Transversely-oblong ; obliquely trun- 

 cated retrally ; concentrically striated, with a few longitudinal 

 ribs behind the fold. 



Tellina rufo maculata, List. Conch, t. cccxciv. — T. incarnata, Venn. Brit. 

 Zool. iv. 88. t. xlvii. f. 31.— T. Fer. Mont. Test. Brit. 55 — P. Fer. 

 Turt. Biv. Brit. 94. — Sandy bays, common. 



Length three quarters of an inch, breadth two inches; reddish, with longi- 

 tudinal rays; compressed; rounded anteally ; concentric striae distinct, espe- 

 cially behind the fold, where they are decussated on the longitudinal ridges, 

 the markings strongest on the left valve ; hinge with two teeth in each valve, 

 one large and bifid. 



— 495. P. soliclula. — Suborbicular, slightly angular retrally, 

 with minute transverse stria?, and distant obsolete ridges of 

 growth. 



& 



Concha parva, List. An. Aug. 175 — Conch, t. ccccv. f. 251. — T. carnaria, 

 Venn. Brit. Zool. iv. 88. t. 49. f. 32 — T. sol. Mont. Test. Brit. 63.— 

 P. sol. Turt. Biv. Brit. 95. — On gravelly shores imbedded near low 

 water-mark. 



Length about three quarters of an inch ; breadth a little more ; white, 

 more or less tinged or banded with pink ; convex ; the cartilage side sloping 

 rather suddenly. 



496. P. rotundata. — Nearly orbicular ; convex ; beaks pro- 

 minent, with numerous obsolete transverse stria?. 



Tellina rot. Mont. Test. Brit. 71- 1. ii. f. 3.— Lucina rot. Turt. Biv. Brit- 

 114. t. vii. f. 3. — South coasts of England and Ireland. 



Diameter about an inch ; yellowish-white ; thin, translucent ; slightly trun- 

 cated retrally ; beaks a little inclining ; hinge with two teeth in one valve, 

 the largest bifid, and slightly diverging ; inner margin slightly striate longi- 

 tudinally. 



