Monia sp.

Raines, Bret & Huber, Markus, 2012, 3217, Zootaxa 3217, pp. 1-106 : 31-33

Monia sp.

Figures 15 A–I

Anomia — Luke, 1995: p. 106.

Material examined. Several single valves (3.6 to 14 mm) from EI (BK) and a single, partly damaged articulated specimen from the SIO Benthic Collection, M1449.

Diagnosis. Shell very small, 14 mm, rather thin, irregularly rounded and rather flat; LV slightly inflated with strong, dense radial riblets or irregular, somewhat spinose ridges; smaller RV thin, fragile and transparent, with byssal foramen. Supradorsal fusing present above the umbones. Prodissoconch, P2 well defined, round, smooth with the exception of growth striae, ca. 220 µm length and 210 µm height. Adult valves yellowish-white to light brown in color.

Remarks. In addition to the few upper valves collected, the ‘ Anomia ’ specimen ( Figs. 15 H–I) noted by Luke (1995) from the SIO Benthic Collection, M1449, was the only articulated specimen encountered. The thinness of the lower valve, the sculpture of the upper valve and the two elongate, central scars ( Fig. 15 B) seem to resemble the genus Monia , than Anomia . The specific identity of this rare species remains unresolved. The type species M. zelandica from New Zealand and M. nobilis ( Reeve, 1859) from the Hawaiian Islands both reach 70 mm and differ substantially in sculpture and color. However, B. A. Marshall (pers. comm., 2011) mentioned a similar species commonly found at Kermadec Islands.

Habitat. Trawled from 40–100 m, La Perouse Bay, Easter Island, 1957/58 Downwind Expedition (DWHD- 76).

Distribution. Although this Monia sp. was found at Easter Island, given that all living anomiids are plankticplanktotrophic developers ( Malchus, 2000b: 245), a westward distribution cannot be excluded at this time— E4.