OCR Text |
Show 1880.] MR. E. A. SMITH ON THE GENUS MYODORA. 581 they agree with the normal Australian form, except that the umbonal angle is rather less acute. 4. MYODORA PANDORIFORMIS (Stutchbury). Analina pandoriformis, Stutchbury, Zool. Journ. v. p. 99, tab. Suppl. 43. f. 3-4. Myodora pandoriformis, Hanley, Rec. Biv. pl. 10. f. 9. M. pandoraformis, Reeve, Con. Icon. f. 10; id. P.Z.S. 1844, p. 93. M. brevis, H. & A. Adams (non Sowerby), Gen. Moll. vol. iii. pl. 98. f. 2, 2a. Hab. Port Jackson (Stutchbury fy Macgillivray) ; Middle Harbour (Angas) ; Sydney Heads, 15 fathoms (Brenchley); Port Philip (Brit. Mus.) ; Stewart Island (C. Traill). This species is easily recognized from the others by its transversely elongate form, its comparative smoothness, and the excessive fineness of the microscopic sculpture. 5. MYODORA CRASSA (Stutchbury). Anatina crassa, Stutchbury, Zool. Journ, v. p. 100, tab. Suppl. 43. f. 5-6. Myodora crassa, Hanley, Rec. Biv. pl. 10. f. 6 ; Reeve, Con. Icon. f. 1 ; id. P. Z. S. 1844, p. 92. Hab. Port Jackson (Stutchbury, Macgillivray, King) ; Middle Harbour (Angas, P. Z. S. 1867); Stewart Island (C. Traill). This species is remarkable for its solidity and its flat valve being less flattened or concave than in other species of the genus. 6. MYODORA OVALIS (Stutchbury). Anatina ovalis, Stutchbury, Zool. Journ. v. p. 100, tab. Suppl. 43. f. 7-8. Myodora ovalis, Hanley, Rec. Biv. pl. 9. f. 53. Hab. Port Jackson. This species, judging from the figure, appears to belong to this genus. It is omitted by Reeve in his Monogragh, by Conrad in his Catalogue in the fourth volume of the ' American Journal of Conchology,' and by Angas in his list of the shells of New South Wales. Stutchbury's description runs thus :-" Shell insequivalve, thin, pellucid, posterior side truncated; right valve convex, superior margin sulcated, receiving the inflated edge of the other valve; left valve slightly convex. Hinge with an oblique elongate internal cartilage. Sinus of the impression of the mantle large." The figure is rather like that of Myodora pandoriformis as regards form ; but the sculpture of the deep valve appears finer. The pallial sinus is said to be large, which is hardly descriptive of that in pandoriformis, or, indeed, of any species of the genus. Indeed, this fact and its " thin, pellucid " substance suggest the possibility of its belonging to another group-Thracia? |