TESTACEOUS MOLLUSCA. 285 



or purple, with twenty-five angulated ribs whose sides are serrated, 

 and angle armed with erect scales, no interstices. 3^...S} . New 

 Holland. 



P. Australis, Sow. Th. f. 210, 220. Suboval, ventricose, 

 thickish, equivalve, inequilateral, anteriorly somewhat spread ; ears 

 unequal, with scabrous sulci ; the twenty-three thick subangulated 

 ribs composed of two rows of small sharp points, and a central 

 ridge with scales, the interstices flat. 1 J. ... 1 ^o* $ wan River. 



P. Varius*. Pen. 4, p. 221, t. 64,/. 1.— Lain. 47.— Mont. p. 

 U6.—Turt. B. p. 214. Sow. Th. f. 214, 218.— Ostrea. V. 

 Lin. \U6.—D.p. 260.— W. t. 10,/. 31.— Bon. t. 1,/. \.—Ch.f. 

 633, 4.— List. t. 180 and 181,/, 18, t. 189./. 23.— (Da Cos. t. 10, 

 /. 1,4, 5,7.) — O. Muricata, Punctata, Versicolor. (Sow. Th. 

 /. 216.) Incarnata, Gmelin. Suboval, thin, not quite regular ; 

 upper valve slightly the larger, the umbones narrow and ventricose ; 

 ears very unequal, rough with muricated sulci, the anterior small 

 and obtuse, the posterior large, acute, and in the upper valve con- 

 siderably overlapping the other at the margin, with the sinus very 

 large : extremely variable in colouring, (when mottled the white 

 patches are usually angulated) the squarish and distant ribs are from 

 twenty-seven to thirty, and muricated by distant erect sharp scales ; 

 the interstices smooth, and rather larger than the ribs. 2|...2. 

 Great Britain and Mediterranean. P. Pusio Lam. (not Lin.) I re- 

 gard as a depauperated variety. 



P. Splendidulus. Sow. Th./. 246. Subtriangular, thin, com- 

 pressed, angulated at the sides, ears very unequal, with scaly sulci, 

 flat, the posterior broad and elongated, the sinus large ; red, banded 

 at the sides and ears with elongated white spots, the twenty-five 

 neat rather distant and rounded subquadrate ribs armed with distant 

 erect and acute scales. l-j ..A^... Singapore. More compressed 

 and regular than the last. 



P. Sanguineus. Lam. 48. — Sow. Th. f. 221,2. — Ostrea, S. 

 Lin. 114.6.— D. p. 259, in part.— Ch. /. 628.— W. t. 10,/. 29. 

 Oval, rather compressed, regular, equivalve, subequilateral; ears 

 unequal, with muricated sulci, the margins elevated, the posterior 

 elongated : the twenty-five thick subangulated ribs armed with nume- 

 ous erect angulated small scales, and toothed at the margin, the 

 interstices narrow and flat : blood red variegated with white or 

 grey. Far. Mottled with black and white. 1 ^...\^ .. .Philippines. 



P. Miniaceus. Lam. 54.— Del. t. 16,/. 6.— Sow. Th.f. 247. 

 Oval, compressed, subequivalve ; ears unequal, with minute scabrous 

 sulci ; red variegated by white undulating patches beneath which 

 the ribs are crossed by minute concentric lines ; the thirty rounded 

 ribs minutely serrated at the sides and annulated by obliterated 

 scales, the interstices flat. l^V"J"iV 



