Chlamys famigerator Iredale, 1925
IREDALE, T. 1925. Mollusca from the continental shelf of eastern Australia. Records of the Australian Museum, 14 (4): 243-270, pls. 41-43. [p. 252, pl. 41, figs. 1, 2]
«CHLAMYS FAMIGERATOR sp. nov.
(Plate xli, figs. 1, 2.) Chlamys antiaustralis Hedley, BioI. Res. F.I.S. "Endeavour," i. 1 1911, p. 96 (specimens from 100 fathoms off Wollongong, N.S.W., not those from 100 fathoms off Oape Pillar, Tas., and perhaps those from 100 fathoms off Cape Wiles, South Australia).
Chlamys antiaustralis Hedley, Check-list Marine Fauna, New South Wales, Mollusca, p. M 8 (Journ. Roy Soc. N.S.W., li, Suppl.), June 19, 1918. Not C. antiaustralis Tate. Shell small, flattened, ears unequal, suborbicular, sculpture peculiar; prodissoconch small, smooth, about twenty-four ribs developed, a little flattened and unadorned at first, then developing lamellae in a discrepant manner on the left valve, more regularly on the right, which is a little more convex. On the left valve the lamellae occur on every third or fourth rib, the intervening ribs remaining smooth. At a little older stage the ribs on the right valve are regularly surmounted by smaller scaly lamellae, the broad interstices are at first concentrically lined but the sculpture becomes irregular and broken with age, and intercalating ribs spring up.
Colour variable; shades of yellow and orange, sometimes pinkish, variegated with white or paler blotches or streaks, internally similarly coloured. Hinge-line straight, narrow, right valve with long ridge bearing minute serration on each side of small ligament pit, with corresponding serrated groove in left valve. Ears: In the right valve the posterior auricle is small, with four wavy radials not much sculptured; the anterior auricle is large, with six radials crossed with erect scales, ctenolium deep. The left valve has the ears unequal, the anterior large with nine radials, distantly scaled, posterior small, with five similarly ornamented radials. Type: Right valve, height 15; breadth, 14 mm.; left valve, height 17 mm.; breadth 16 mm. Off Green Cape, 50-70 fathoms (R. Bell), type locality. Off Bateman's Bay, 75 fathoms (Mulvey). Off Eden, 30 fathoms (Livingstone and Fletcher). Off Wollongong, 100 fathoms (Hedley). Apparently well distributed, but no large specimens yet recognised. This species is allied to Pecten (Chlamys) dichrous Suter [17] , from New Zealand, which Suter refers to the neighbourhood of the Miocene fossil Pecten chathamensis Hutton [18], but I have not yet traced the Australian fossil representative. The New Zealand dichrous measures as much as 32 mm. by 36 mm., retaining the peculiar sculpture, so that the Australian shell may also continue with the erratic ornamentation, though at first sight this seems doubtful. The species, fossil and recent, of the asperrimus [19] group are in a chaotic state, owing to the variability of the common shell, and it has been a difficult task to separate the present species. Roy Bell sent me an extensive series of large and small shells and valves of Chlamys from Twofold Bay, 20-25 fathoms, and off Green Cape, 50-70 fathoms. After as many as possible were referred to asperrimus, three distinct species could be recognised: the one here named, another unnamed form, and one determined as blandus Reeve [20], but the lastnamed seemed a form of asperrimus with peculiarly well-developed lamellae. The reference of the present species to C. antiaustralis Tate seemed doubtful, and upon application to Mr. F. A. Singleton, of the University of Melbourne, he forwarded me a series of the species recognised by the Victorian palaeontologists as Tate's species. These agreed with Tate's description, but were specifically inseparable from the shell regarded as Lamarck's asperrimus. Consequently, if' any species were to be called antiaustralis, it would be a deepwater shell, such as we now regard as asperrimus. The two species here described have been confused and recorded as antiaustralis, but they are clearly separable, the young of the large species being of a different shape when equivalent in size to the smaller species.» 17 Suter — Proc. Malac. Soc. (Lond.), viii, 1909, p. 264, pI. xl, fig. 31.
18 Hutton — Cat. Tert. Moll. New Zeal., 1873, p. 29. 19 Lamarck — Hist. Anim. s. Verteb., vi, 1819, p. 174. 20 Reeve — Conch. Icon., viii, 1853, pI. xxxiv, sp. and fig. 162. TOM IREDALE, 1925
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T. Iredale, 1925, plate 41.
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