TESTACEOUS MOLLUSCA. 273 
often light reddish brown banded and variegated with purplish 
brown, much lighter on the lower valve; there is also a bright 
orange variety and a white one. Variety. P. Lineatus. Da Cost. 
t. 10. f. 8.—Mont. p. 147.—Lam. 35.—Ostrea L. Don. t. 116. 
—D. p. 266.—W. t. 11. f. 44. White with a red line on the 
top of each rib. 2-5,...24. Britain, Mediterranean. 
P. Avpouinu. Payr. p. 77. t. 2, f. 8—P. Susrurus. 
Sow. Th. f. 208, 9, 10.—Suborbicular, rather compressed, 
anteriorly subattenuated, scabrous; ears nearly equal, stri- 
ated, obtuse, the posterior of the lower valve rather large and 
emarginated at the base; ribs twenty, angulated, their angles 
serrated 3 the sides concentrically striated, the interstices with 
scabrous striz : colour variable, reddish brown with white ziczacs, 
purple, variegated, and pale orange variegated with brown and 
white. 22%..23. Mediterranean. The Subrufus of Pennant is a 
variety of the last. : 
P. Exasrrratus. Sow. Th. t. 183. f. 186. Rounded-subqua- 
drate, rather ventricose, scabrous; ears large, with scabrous strie; 
ribs eighteen, subangular, the angles serrated, the sides with ser- 
rated striz, the interstices with scabrous striz; variations of 
colouring similar to the last. 1...49. Mediterranean. 
P. Brrrons. Lam. 4.—Reeve. Sys. t. 114*. f. 8.— Sow. Th. f.9, 
10. Subequivalve, subequilateral, orbicular, posteriorly less 
spread, scabrous; ears broad, quadrate, striated, the anterior 
slightly the smaller; with nine little elevated, rounded ribs, ar- 
ranged in twos or threes; interstices broad, with irregular radia- 
ting ribs; upper valve pale purple, with blackish-red ribs which 
are spotted near the umbones; lower valve white, the ribs red; 
purple within, 24..22. 
P. Pataconicus. King, Z. J.—Sow. Th. f. 60. Rounded, 
rather ventricose, nearly smooth; ears striated and obtuse, the 
posterior the larger; pale fawn with thirty-four reddish brown 
nearly square smooth and elevated ribs. 22,..22. Patagonia. 
P. Soraris. Born. t.6. f. 4.—Sow. Th. f. 7, 8, 22.—Phil. Conch. 
Pecten. t. 2, f. 2.—Ostrea S. D. p. 264. Rounded, subequivalve, 
subequilateral, flat; ears small, nearly equal, smooth; pale red 
variegated with irregular bands and lines of red and white, or white 
with irregular bands of red spots; with eighteen smooth rounded 
and equal ribs having their interstices broad and substriated ; in 
the lower valve, the ribs are broader, more or less striated and with 
scarcely any interstices. 23..2.;.  Macassar § China. 
P. Osriteratus. Lam. 8.—Sow. Lh. f. 126.—Osrrea O. Lin. 
1146.—WV, tf. 10. f. 25.—Gualt. t. 73. f. C.—D. p. 258.—Kunorr. 
5, t, 21. f. 6, Suboval, smooth, semitransparent, compressed, 
T 
