21 
perforated at the apex ; aperture small, elliptical. 
Operculum bivalve. 
P. Anciicum. Sow. G. f. 7.—Reeve t. 10. f. 7. 
—Apna A." Leach.—An P. Suucatum ? Philippi. p. 
252. t. 12. f.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.—LeEpas V. Ch. f. 834:— 
Turt. D. p. 79.—Gmel. 3212.—Wood G. C. p. 57. 
t.9. f. 5—L. Stroma. Muller, Zool, Dan.3. t. 94. 
f. 1.—D. p.19.—OcutHosia 8. Philippi. p. 251.— 
Bl. t. 85. f. 4.—Striata. Pen. 4. p..73. ¢.37. f. 7. 
Bauanus 8. Da. Cos. p. 250.—Mont. p. 12.— 
L. INTERTEXTA. Don. ¢. 36. f. 1—Cuirea V. Sow. 
G. f.2.—Reeve. t. 8. 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 bya tubular coriaceous flexrble peduncle 
