364 MOLLUSCA. FISSURELLAD.E. Fissurella. 
Shells, t. xxi. f. 1. Mmt. Brit. Shells, 486. — On rocks and shells in 
rather deep water. 
Breadth sometimes reaching to an inch and a half ; white, with a carna- 
tion tinge ; cuticle brown, rough with a pilose margin ; aperture round, 
slightly waved. 
360. C. antiquatus. — Apex blunt, the layers of growth form- 
ing concentric scale-like wrinkles. 
Patella rugosa. List.. Conch, t. Dxliv. f. 31. ? — ^P. ant. I Ann. Syst. i. 1259. 
Pult. Dorset. 51. — Mont. Test. Brit. 485 — On different parts of the 
coast, rare. 
Breadth about half an inch ; thick, opake, white, apex variable in form ; 
' aperture oval or round. 
361. C. militaris. — Shell decussated by longitudinal and 
transverse striae. 
Patella alba. List. Conch, t. Dxliv. f. 32. — P. mil. Pult. Dorset. 51. Don. 
Brit. Shells, t. clxxi. Mont. Test. Brit. 488. t. xiii. f. ll.— On diffe- 
rent parts of the coast, rare. 
Breadth about half an inch ; subpellucid, white ; cuticle brown, pilose ; 
apex much reflected and recurved ; aperture round ; inside glossy white. 
EXTINCT SPECIES. 
1. C. Depressed, suborbicular, obscurely radiated ; vertex ob- 
lique, recurved, extended beyond the base, acute. — Patella unguis. Sower. 
Min. Conch, t. cxxxix. f. 7* — In Crag, Holywell. 
FISSURELLADiE. 
Gen. LXXXVIII. FISSURELLA.— Shell ovate, conical, 
with a perforated apex ; tentacula with eyes at the external 
base. 
362. F. grcBca.-^0\3\, decussated by unequal longitudinal 
ribs and transverse striae ; apex truncated. 
Patella cancellata. List. Conch, t. nxxvii. f. 2. — P. grteca, Linn. Syst. i. 
1262 Penn. Brit. Zool. iv. 144. t. Ixxxix. f. 153 P. reticulata, 
Don. Brit. Shells, t. xxi. f. 3. — Western coasts, not common. 
Length of the aperture about three quarters of an inch, breadth half an 
inch ; height a quarter ; thick, brown, inside white or rayed with brown ; 
perforation of the apex oblong ; margin of the aperture waved, crenulated. 
363. F. apertura. — Conical, with a reflected subspiral apex. 
Patella apertura, Mont. Test. Brit. 491. t. xiii. f. 10. — South of England 
and Zetland. 
Length about |ths, height |th, subpellucid, white, strong, the longitudinal 
tubercled ribs crossed by a few circular ridges ; apex adhering, the perfora- 
tion in front rhomboidal ; margin of the aperture oval, crenated by the ribs. 
