TRIBE MACTRACEA. 37 
abrupt and rounded ; epidermis fibrous ; umbones small and striated : 
inside somewhat fuscous. 11..13.— Philippines. 
C. AnrittARUM. Reeve. Z. P. 1841. § Ic. f. 8. Ovate-tri- 
angular scarcely gibbous, thick, anteriorly sub-angulated, posteriorly 
rounded ; epidermis fibrous : umbones somewhat depressed and 
slightly undulated : inside rich chocolate brown becoming pale and 
whitish towards the margin. 21..34.—W. Indies. 
C. Jusar. Reeve. Z. P. 1841. § Ic. f. 11. Sub-ovate, very 
inequilateral, gibbous, posteriorly inclined and rounded, anteriorly 
arcuated; with brilliant rust coloured expanding rays under a fuscous 
here and there bruised epidermis, the sides marked with numerous 
irregular striz ; umbones compressed and plicated: inside white, 
anteriorly brown. 13..23.—W. Australia. 
C. Corsutoripes. Reeve. Z. P. 1841. §& Ic. f. 9. Sub-orbi- 
cular, very gibbous, deeply grooved towards the umbones, epidermis 
brown : posteriorly rounded, anteriorly produced and suddenly 
rostrated. 1..13. 
C.Ziczac. Reeve. Z. P. 1841. & Ic. f. 13. Sub-triangular, 
depressed, yellowish under a thin epidermis, with flexuous rosy 
linear markings and two interrupted rays ; anteriorly sub-angu- 
lated, posteriorly shortish and rounded: lunule on each side bril- 
liantly banded with rosy rays: within somewhat rosy. 1..13.—~ 
Philippines. 
C. Triauetra. Reeve. Z. P. 1841. & Ic. f. 14. Triangular, 
solid, rosaceous under a thin epidermis, brilliantly painted with 
deep pink spots, and transversely striated ; sides nearly straight and 
searcely rounded ; lunule on each side large, and brilhantly banded 
with rosy rays : inside rosaceous becoming white towards the finely 
crenulated margin. &..7. 
C. Ornata. Reeve. Z. P. 1841. § Ic. f. 17.—Mersopesma O. 
Gray in Grif. Cuv. Triangular, somewhat depressed, anteriorly 
flexuous and angulated, posteriorly rounded: pale with transverse 
strize and short longitudinal chesnut linear markings : within white 
and brown, the margin finely crenulated. 4..1%. 
C. Unputata. Sow. Z. P. 1832.—Reeve. Ic. f. 2. Oval, 
brown spotted with fuscous under a fuscous epidermis; within 
brown becoming white posteriorly ; the umbones undulated ; the 
posterior side inclined and rounded ; the anterior the longer, acumi- 
nated and angulated. 13..2,%,.— Central America. 
C. Gissosa. Sow. Z. P. 1832.—Reeve. Ic. f. 1. § Sys. t. 
44. f. 2. Sub-oval, gibbous, rather pale, under a brown epidermis ; 
within whitish but anteriorly brown ; the umbones undulated and 
compressed ; the posterior side inclined, rounded, with a few short 
grooves ; the anterior arcuated, elongated, and acuminated. 1{.. 14. 
—S. America. 
C. Raprata. Sow. Tank. Cat. t. 1. f. 2.—Reeve. t. 44. fr 1. 
