260 TESTACEOUS MOLLUSCA. 
thin, fragile, blue or purplish, with a dark brown almost black 
subradiated epidermis ; hinge-margin elongated and straight; an- 
terior margin direct and emarginated. 14.—Sandwich Isles. | 
MALLEUS. 
Subequivalve, rugged, distorted frequently elongated ; sublobate at 
the top; beaks small, diverging ; hinge without teeth, with an 
elongated conical furrow under the beaks ; ligament subexternal, 
short, placed in the sloping area, at the top of the valves. 
M. Atsus. Lam. 1. Ostrea Matuevus Asus. Ch. f. 2029,0. 
—O. Mateus Var. D. p. 273.—Hammer-shaped, the hinge-mar- 
gin being elongated on either side of the subcentral beaks, and the 
shell being produced ventrally in an elongated narrow, very tortu- 
ous, (generally) straight lobe, white usually speckled with rust-co- 
lour : smooth, the small portion of internal nacre bluish black : beaks 
scarcely projecting. Young. M. Normatis Sow. G.—Reeve t. 
107. f. 2.—Osrrea Anatina WV, ¢. 11. f. 59. The anterior lobe 
not yet developed. 8. Australia. China? No particular sinus 
for the byssus. 
M. Vutearis. Lam. 2.—Sow. G.—Reeve. Sys. t. 107. f. 1.— 
Bl. t. 63. f. 4.—E. t.177. f. 12.—Ostrea Matrevs Lin. 1147. 
—D. p. 272.—Ch. f. 655.—W. t. 11. f. 58. Shape of the last, but 
black, coarse, more tortuous; the sinus for the byssus distinct from 
the ligamental cavity. 8. Indian Ocean. The figure 656 of Chem- 
nite is considered by Lamarck, a white variety of this species. 
M. Normatuis. Lam. 3.—Del. t. 14. f. 4, 5.--Elongated, 
broad, tortuous, the dorsal edge forming an anterior lobe, but no 
posterior one. Var. A. Yellowish, speckled with brown, and 
within whitish, with the space occupied by the animal, bluish black ; 
the lobe short. Yar. B. Black, anterior lobe long. 5. Australia, 
the var. B. Indian Ocean. Distinguished from the young of Albus by 
the lobe being anterwr, and the shell broader in proportion, from 
Vulsellatus by being tortuous. 
M. Vursettatus. Lam. 4.—Bl. t. 65. bis. f. 4.—Ostrea 
Recura Forskael Desc. Anim. p. 124.—Ch. f. 657.—D. p. 278. 
Elongated, flattened, purplish black, lamellar, flexuous but not tor- 
tuous, narrow edges of the sides subparallel : hinge margin short, a 
very small anterior lobe; a distinct bysseal sinus: internal nacre 
white, the scar black. 6. Red Sea, Madagascar. 
M. Anartinus. Lam. 5.--Ostrrea A. Gmel. 3333.—O Fiev- 
rata. D. p. 273.—Ch. f. 658,9.—E. ¢. 177. f. 14. Oblong- 

1 See too P. Quaprata of Anton in Wiegman’s Archives, 1837, 
also P. PLanorpis and Ruretya of Dufo in the Ann. de sc. nat. 2d. 
series vol. 14. 
