Platymma tweediei Tomlin, 1938
Tomlin (1938) original descriptions on Platymma tweediei – “… has fairly regular and regularly spaced growth lines, and under a strong lens very faint spirals can be detected on the upper half of the earlier whorls; the effect of the growth lines on the protoconch is to give it somewhat the appearance of an ammonite. It is a very fine shell, measuring nearly 3 inches across, flattened, with 6 ½ whorls, dark brown in colour, becoming slightly darker both above and below the periphery and lightening again round the umbilicus though there is no sharply defined line of change as there is in floweri. Aperture long-oval, somewhat flattened above, umbilicus broad and deep – more so than in floweri.
“The jaw is thick and solid, somewhat arched in the middle with a distinct forward projection not so prominent as that of Hemiplecta floweri described by Godwin-Austen in these Proceedings, vol. 4, p. 32, and figured in plate 54, fig. 10. The radula has 150 fully developed rows of teeth with formula 154.1.154. The formula for H. floweri is given as 101.1.101. The central and admedians have strong cones with lateral swellings that do not amount to ectocones. The first twenty laterals resemble the admedian, they then become narrower with shorter bases. From about line 30 the cones increase in length until lines 40 to 70 form a group of inner marginals that overlap the succeeding row of teeth. Outside these the teeth get gradually shorter while at about line 90 some of the teeth show a swelling on the outer face which by line 100 has developed to make the tooth bicuspid. These bicuspid teeth are rather irregularly formed, the position of the second cusp being variable. By line 130 the teeth are comparatively small; the outermost twenty lines are rudimentary and become more and more shapeless at the extreme margin of the radula.” (Tomlin, 1938)
Platymma tweediei – “Diam. max. 72-79 mm., diam. min. 55-60.6 mm., alt. 38-44 mm.” (Tomlin, 1938)
Type locality – “Kuala Terla, Telom Valley, Cameron Highlands, Pahang” leg. M. W. F. Tweedie (Tomlin, 1938)