Propeamussium, de Gregorio, 1884

Dijkstra, H. H. & Maestrati, P., 2015, Pectinoidea (Bivalvia: Propeamussiidae and Cyclochlamydidae) from the southwestern Indian Ocean, African Invertebrates 56 (3), pp. 585-585 : 587

Key to species of Propeamussium in the southwestern Indian Ocean – Shell large, slightly oblong, weakly commarginally sculptured .............................1

1 Shell 58 mm high, hYaline, lv with fine commarginal lirae, prominent commarginal sculpture near ventral margin, 9–11 variable in length, delicate internal ribs .......... ....................................................................... P. andamanicum (E.A. Smith, 1894)

– Shell small, circular, flattened, weaklY sculptured.................................................. 2

2 Shell 15 mm high, hyaline, lv creamy or reddish, rv whitish, 7 prominent internal ribs................................................................ P. arabicum Dijkstra & Janssen, 2013

– Shell oblong, auricles somewhat raised ..................................................................3

3 Shell 29 mm high, hyaline, brownish, lv smooth and glossy, 10 internal ribs slightly nodulose at distal ends ........................................... P. caducum (E.A. Smith, 1885)

– Shell almost circular, flattened, weaklY latticed sculptured ....................................4

4 Shell 28 mm high, semi-transparent, lv orange-brownish, rv whitish, 10 internal ribs........................................................................... P. jeffreysii (E.A. Smith, 1885)

– Shell almost circular, flattened, earlY ontogenY smooth and glossY .......................5

5 Shell 25 mm high, semi-transparent or opaque, orange-brownish tinted, 9 internal ribs................................................................................................... P. rosadoi sp. n.

– Shell large, circular, lv with delicate commarginal growth lines ............................6

6 Shell c. 55 mm high, hyaline, creamy or brownish, lv almost smooth, 8 strong, broad internal ribs............................................... P. sibogai ( Dautzenberg & Bavay, 1904)

– Shell large, circular, rather solid, lv radially sculptured..........................................7

7 Shell c. 60 mm high, opaque, whitish, lv with delicate radial sculpture in early growth stage, commarginal lamellae near ventral margin, 10 internal ribs........................... ................................................................................... P. watsoni (E.A. Smith, 1885)