Mirapecten bornhardti (Cox, 1927)
COX, L. R. 1927. Neogene and Quaternary Mollusca from the Zanzibar Protectorate. In Anonymous (Eds.): Report on the Palaeontology of the Zanzibar Protectorate based mainly on the collection made by G. M. Stockley: 13-102, pls. 3-19. Published by Authority of the Government of Zanzibar. [p. 76, pl. 17, figs. 1-3]
1927 Chlamys (Aequipecten) bornhardti Cox, 1927
L. R. Cox, 1927, plate 17.
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«(Named after W. Bornhardt, a pioneer in the investigation
of E. African geology). Specific characters:—Shell of medium size, sub-equivalve, moderately inflated, sub-equilateral, fan-shaped, with the length equal to, or slightly in excess of, the height. Right valve sculptured with 10-12 wide, rather depressed rounded costae, each ornamented. longitudinally with 3-5 linear riblets, which sometimes (especially the middle one) are broken up into small tubercles; intercostal spaces quite smooth, of about the same width as the coste; ears fairly large, subequal, the posterior one usually smooth, the anterior one smooth or ornamented with about four noduled riblets; byssal notch moderately deep, ctenolium small. Left valve sculptured. with 9-12 costae, which are sometimes similar to those of the right valve, but usually are ornamented with definite tubercles along their crests; certain of these costae (usually five, symmetrically disposed) usually bearing at regular intervals (about 15mm. apart) very prominent, erect scales; ears large, subequal, obscurely ribbed. Interior of shell ornamented with wide, concave ribs, most conspicuous near the ventral margin, their positions determined by the intercostal spaces of the exterior; cardinal crura weak, two pairs occurring in the right valve and one pair in the left ; hinge-area with a faint striation perpendicular to the hinge-maryin.
Localities:— Zanzibar 14, 35, 37 and 55 (type-loc.). Material:— The holotype (L. 44031), a right valve, and thirteen paratypes, of which six are left and seven right valves. Dimensions:— The holotype, which is the largest specimen, measures: length 50mm., height 48mm., inflation 8mm. Remarks:— Although no specimen was collected with both valves together, there can be no doubt that the strongly scaled left valves belong to the same species as the much more smoothly costate right valves. Each of the above locatities has yielded both left and right valves, associated together in the same piece of rock. The symmetrically disposed, scaled ribs of the left valve suggest comparison with the living Indian Ocean species, Chlamys mirifica (Reeve), but the ornament of the right valve of that species is entirely different from that of the right valve of C. bornhardti. There is no other described species with which C. bornhardti could be confused.» LESLIE REGINALD COX, 1927
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«Locality. No. 4 [Cliff, north-east of Mombasa, south of the Ras Makawe Jini] (two specimens, C. W. Hobley and McKinnon Wood Colls.).
Further Distribution. Pliocene of Zanzibar, and Northern Ceylon. Remarks. In these specimens, both of which are broken right valves, the ribs are grouped in pairs. In Zanzibar specimens they are quite evenly distributed.» COX, L. R. 1930. Reports on Geological Collections from the Coastlands of Kenya Colony made by Miss M. McKinnon Wood. V, VI, VII : Miocene, Pliocene, Post-Pliocene Mollusca. Monographs of the Geological Department of the Hunterian Museum, Glasgow University, 4: 103-163, pls. 12-15. [p. 124]
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Chlamys (Aequipecten) bornhardti, Cox; L. R. Cox, 1930, Reports on Geological Collections from the Coastlands of Kenya Colony made by Miss M. McKinnon Wood, plate 14, figures 7, 8.
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«1927. Chlamys (Aequipecten) bornhardti Cox, (13), p. 76, PI. 17, figs. 1-3.
1930. Chlamys (Aequipecten) bornhardti Cox, Cox, (15), p. 124, PI. 14, figs. 7-8. Material:— Sample APT.50 (Zanzibar, in Stockley's Cave at S.E. edge of Kijini Hill; L. Miocene, with Lepidocyclina), 11 specimens; sample APT.82 (Zanzibar, spoil from well N. of road at Kwebona; L. Miocene, with Lepidocyclina), 1 specimen: sample REL.2323 (Zanzibar, between Mtoni and Masingini Ridge; L. Miocene), 1 specimen; sample APT.106 (Zanzibar, E. coast of Tumbatu I., 2,000 yds. S. of Gomani; Pliocene), 2 specimens; sample REL.3006 (Kenya, Mtwapa Creek, N. side, 1½ miles up from ferry; Pliocene), 3 specimens.
Remarks:— Previous records are from the Pliocene of Zanzibar and N. Ceylon, but some of these probably refer to L. Miocene occurrences. The present evidence indicates that the species must be regarded as ranging from L. Miocene to Pliocene.» EAMES, F. E. & L. R. COX. 1956. Some Tertiary Pectinacea from East Africa, Persia, and the Mediterranean region. Proceedings of the Malacological Society of London, 32 (1): 1-68, pls. 1-20. [p. 42]
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