28 



the valves toothed or plaited. Hinge with four teeth on 

 each valve : the two cardinal approximate and oblique, 

 articulating crosswise with the corresponding teeth of the 

 other valve; the two lateral teeth distant, entering". The 

 ligament is external and very short; and there are two 

 faint muscular impressions. 



* C. EDULE. Turt. Lin. Pen. Brit. Zo., pi. 50, fig. 41. 

 Mont. Test. Brit., vol. 1, p. 76, Flem. Brit, An., p. 422. 

 Common Cockle. Common in harbours that have a stream 

 of fresh water; from whence they are taken in abundance, 

 and carried to market. 



This shell varies so considerably, as almost to raise the 

 suspicion of a difference of species. In its younger state it is 

 about equal-sided, the ridges smooth; but when fully grown 

 in an undisturbed situation, the hinge is nearer one end, the 

 opposite margin produced, and the ridges thickly and regu- 

 larly covered with raised transverse edges. A considerable 

 quantity in this state, of large size, and mixed with Vene- 

 rirupis Decussata, V. Virginea and others, were found with 

 other ancient animal remains, in the stream work of Lower 

 Pentewan, near St. Austle. 



* C. ECHINATUM. Turt. Lin. Mont. Test. Brit., vol. 1. 

 p. 78. Flem. Brit. An., p. 420. Prickly Cockle. Not 

 uncommonly taken in the Trawl. 



* C. TUBERCULATUM, Mont. Test. Brit., vol. I, p. 79, 

 and vol. 2, p. 568. Flem. Brit. An., p. 421. The loose 

 valves are scattered along our shores; and in some places 

 in abundance, as in Lantivet ha}', east of Fowey. 



C. CILIARE. Turt. Lin. Mont. Test. Brit., vol. 1, p. 80. 

 Fleming supposes this to be the young state of C. Acu- 

 leatum. Pen. Brit. Zo., vol. 4, pi. 50, fig. 39. Mont. 

 Test. Brit., vol. 1, p. 77. A shell so slight and fragile as 

 this, will scarcely be found abundant on the shore; hence 

 the on iv place at which I have discovered it, is Pentewan. 



* C, EXIGUUM. C. Pygmeum. Turt. Lin. C. E. Mont. 

 Test. Brit., vol. 1, p. 82. Flem. Brit. An., p. 422. This 

 shell belongs to Lamark's sub-section, in which the valve 

 has a carination or angle, dividing the surface into two 

 unequal longitudinal spaces. Not uncommon near low 

 water mark. 



* C. MEDIUM. Turt. Lin. Mont. Test. Brit., vol. 1, p. 83. 

 Fie id. Brit. An., p. 422. This shell bears much resem- 

 blance to the last; but it is larger, and without tubercles 

 cr spines.. t found it in abundance in the soil taken up 

 for the purpose of deepening the harbour, at Falmouth. 



C. NODOSUM. Mont. Test. Brit., vol. 1, p. 81. "With 

 a fiat suborbicular shell; colour rufous white, with 24 ribs, 

 covered with close set, obtuse tubercles. Inside white 



