21 



perforated at the apex ; aperture small, elliptical. 

 Operculum bivalve. 



P. ANGLICUM. Sow. G.f. 7. Reeve t. 10. /. 7. 

 ADNA A/ Leach. An P. SULCATUM ? Philippi.p. 

 252. t. 12./. 24. Not uncommon in Devonshire, very 

 small. 



GENUS CREUSIA. 



Sessile, fixed, orbicular, convex, conical, quadrivalve ; 

 valves unequal, united, distinguished by their 

 sutures : operculum internal, bivalve. 



C. VERRUCA. Lam. 3. LEPAS V. Ch. f. 834- 

 Turt. D. p. 79.Gmel. 3212. Wood G. C. p. 57. 

 t. 9./. 5. L. STROMIA. Muller,Zool, Dan.3. t. 94. 

 /. 1. D.p. 19. OCHTHOSIA S. Philippi.p. 251. 

 Bl. t. 85./. 4. STRIATA. Pen. 4. p. 73. t. 37. f. 7. 

 BALANUS S. Da. Cos. p. 250. Mont. p. 12. 

 L. INTERTEXTA. Don. t. 36. /. 1. CLITEA V. Sow. 

 G.f. 2. Reeve, t. S. f. 2. Compressed, white, the 

 valves strongly ribbed obliquely to each other and finely 

 striated across the ribs, the margin of the base irre- 

 gularly serrated : aperture oblique, perfectly closed by 

 an operculum, and so obscure that it is difficult to find, 

 except when alive. . Not uncommon. Kent, Devon, 

 Dorset. 



ORDER PEDUNCULATA. 

 Body supported by a tubular coriaceous flexible peduncle 



