Complicachlamys Iredale, 1939

Dijkstra, Henk H. & Beu, Alan G., 2018, Living Scallops of Australia and Adjacent Waters (Mollusca: Bivalvia: Pectinoidea: Propeamussiidae, Cyclochlamydidae and Pectinidae), Records of the Australian Museum (Rec. Aust. Mus.) 70 (2), pp. 113-330 : 227

Complicachlamys Iredale, 1939

Complicachlamys Iredale, 1939: 362 . Type species (by original designation): Complicachlamys wardiana Iredale, 1939 ; Recent, QLD, Australia.

Diagnosis. Elongate, medium-sized Pedini with 7–9 primary radial plicae and numerous secondary radial costae; valves flattened, subequilateral; interstitial commarginal sculpture present, but no shagreen microsculpture; auricles very unequal, anterior large, posterior small; hinge teeth small, with obsolete resilial teeth and prominent dorsal teeth, intermediate teeth lacking; byssal notch deep, ctenolium well-developed.

Distribution. Recent. Tropical southwestern Pacific, living in the littoral zone, bysally attached to rocks or other hard substrates.

Discussion. Iredale (1939: 362) introduced Complicachlamys and included several “representative” species, viz. Complicachlamys fulvicostata A. Adams & Reeve, 1850 [sic], Complicachlamys luculenta Reeve, 1853 [sic] = Complicachlamys dringi Reeve, 1853 [sic], and Complicachlamys crouchi Smith, 1892 [sic] [all the authors and years should have been placed between parentheses]. All these species have shagreen microsculpture and should be placed in Semipallium [Jousseaume] Lamy, 1928. Complicachlamys wardiana does not have this peculiar microsculpture, although Iredale (1939: 362) mentioned sculpture in the interstices of the secondary radial costae “producing a honeycomb effect”, which is somewhat similar to the shagreen sculpture of Semipallium species. Complicachlamys wardiana has interstitial commarginal sculpture of curved lamellae, producing hollow sections on most specimens. Other characters (outline, primary plicae and secondary costae, highly unequal auricles, deep byssal notch, well-developed ctenolium) are almost indistinguishable from those of Semipallium , and it is possible that C. wardiana is simply a species of Semipallium that has lost shagreen sculpture. This would be resolved best by comparison of DNA sequences.

Hertlein (1969: N366) treated Complicachlamys as a junior synonym of Semipallium , and was followed by Vaught (1989: 119). Wagner (1989b: 111) considered Complicachlamys to be a junior synonym of Chlamys Röding, 1798 .