Cryptoplax menkrawitensis Beets, 1941

Schwabe, Enrico, Sirenko, Boris I. & Seeto, Johnson, 2008, A checklist of Polyplacophora (Mollusca) from the Fiji islands, Zootaxa 1777, pp. 1-52 : 31-32

? † Cryptoplax menkrawitensis Beets, 1941

( Figure 13 )

Cryptoplax menkrawitensis Beets 1941: 8 , pl. 1, figs 1–3.

Locus typicus: Indonesia, Borneo, Kalimantan Timur, Tanjung Mangkalihat, Menkrawit-beds (Upper

Miocene) [01°01’N 118°59’E].

Primary type: Holotype (RGM.312.201), part of the Leopold collection, not seen. Fiji record: Cryptoplax cf. C. menkrawitensis ; Ladd 1966: 24, pl. 1, fig. 22. Cryptoplax sp.; Ladd 1966: 25.

Material examined: USNM 648221: 1 intermediate valve from the Miocene Suva Formation (Tertiary f)

at Viti Levu, Station 160; USNM: 1 tail valve + 4 intermediate valves from the Miocene Suva Formation (Ter-

tiary f) at Viti Levu, Station 160.

Remarks: While the species was originally described from the upper Miocene of the Mangkalihat peninsula of East Borneo, the material Ladd mentioned was collected at the Miocene Suva Formation at Viti Levu and consists of three intermediate valves and one tail valve. He illustrated an intermediate valve (Ladd 1966, pl. 1, fig. 22.; here fig. 13A), which was the only valve in the sample USNM 648221, suggesting that two intermediate valves and a tail valve are missing. Coexisting with the above listed valves Ladd (1966: 25) reported four intermediate valves and a tail valve of Cryptoplax sp., which “may represent a distinct species”. Based on the examined valves the species can not attributed to one of the living congeners with certainty but are here interpreted as belonging to one species although one of the valves ( Fig. 13E ) may not belong with the others. The most similar species seems to be Cryptoplax striata (Lamarck, 1819) , while the original description of C. menkrawitensis fits well to the sculpture of our Cryptoplax sp. presented herein.

Figures

FIGURE 13. A – F,? † Cryptoplax menkrawitensis Beets, 1941 A, dorsal view of a tail valve (USNM 648221) from the Miocene Suva Formation at Viti Levu, Station 160. B – F, unregistrated material from the same locality as in Figure A. B, D, F, dorsal view of intermediate valves. C, dorsal view of a tail valve. E, most probably a second valve, dorsal view. Scale bars 1 mm.