U2 MOLLUSCA. LUCINADiE. Lucina. 



Pectunculus subfuscus, List. Conch, t. ccxciii — Tellina radula, Mont. 



Test. Brit. G8. t. ii. f. 1, 2— Venus borealis, Don. Brit. Shells, t. cxxx, 



— L. radula, Turt. Biv. Brit. 116 — Deep water on various parts of the 



coast. 



Diameter about an inch and a half; white; lenticular, the margin slightly 



irregular retrally ; beak prominent, slightly inclinmg ; the concentric striae 



in the _voung shell are very regular (in which slate it appears to be the L. alba 



of Dr Turton, Biv. Brit. 114. t. vii. f. 6, 7-)? hut with age they become in-e- 



gular, and less distinct towards the margin ; one of the hinge teeth cloven ; 



right valve with an anterior lateral tooth. 



505. l^.Jlexuosa. — Obsoletely striated transversely; the beaks 

 prominent, and the retral margin much waved. 



Tellina flexuosa, Mont. Test. Brit. 72 — Cryptodon flexuosus, Turt. Biv. 

 Brit. 121. t. vii. f. 9, 10 — Not uncommon from Devon to Zetland. 

 Diameter scarcely half an inch ; white, thin and translucent ; two grooves 

 on the retral extremity, extending from the beaks to the margin, and a 

 rounded depression before the beaks ; the teeth are indistinct, seldom more 

 than one tooth developed in each valve. It bears a very close resemblance 

 to L. pennsylvanica. List. Conch, t. cccv. 



** StricB oblique and arched (Strigella of Turton). 



506. L. camaria. — Oval, inequilateral, with oblique striae in 

 three directions, forming acute angles retrally, and waved arches 

 anteally. 



Pectunculus tenuis. List. Conch, t. cccxxxix. — Tellina carnaria, Linn. 



Syst. i. 1119 PuU. Dorset, xxx — Do7i. Brit. Shells, t. xlvii Mont. 



Test. Brit. 73 — Strigilla camaria, Turt. Biv. Brit. 117 — Weymouth 

 and Poole, Dr Pulteney. 

 Diameter about ^ths of an inch; white, more or less tinged with rose-co- 

 lour, back a little inclining, under which is an oval impression. 



507. L. pisiformis. — Shell somewhat globular, and nearly 

 equilateral, with oblique longitudinal striae on one side, forming 

 acute angles, on the other waved. 



Tellina pisiformis, Linn. Syst. i." 1 1 20. — Cardium discors, Mont. Test. 

 Brit- <54 Strigilla pisiformis, Turt. Biv. Brit. 119 — One dead speci- 

 men fouiad at Falmouth by Mr Montagu. 

 Diameter about a quarter of an inch ; convex, "lossy white ; beaks smaU, 

 inclining ; two teeth in one valve, one of which is very small, one in the 

 otlier, with remote lateral teeth like laminoe. The Strigilla divaricata of 

 "• Bivalvia Britannica," appears to belong to this species. " Shell half an 

 ir^h in diameter, white, thin, brittle, orbicular, with a slight flexuosity on 

 the hinder side, rather convex, with regular but not very close striae, which 

 form rather oblique curved lines, and turn oif at both the sides nearly in 

 right angles ; beaks central, very prominent ; hinge with a single cloven 

 tooth in one valve, closing between t^vo plain ones in the other ; the lateral 

 teeth remote and small." Shores of Teignmouth. 



508. L. arcuata. — Orbicular, with oblique doubly waved striae. 



Cardium ar. Mont. Test. Brit. 85. t, 3. f. 2 — Falmouth harboiir. 



Diameter about half an inch ; white, thin, fragile, finely and regularly 

 striated obliquely, with a few irregular concentric furrows ; beak central, 

 pointed and arching; liinge with one primary tooth in each valve, lateral 

 teeth remote 



