Onoba semicostata (Montagu, 1803)

(Fig. 21f)

Material examined. (2 empty shells in 2 samples): SPAIN • 1 sh 42° 30.391′ N, 009° 19.517′ W to 42° 29.428′ N, 009° 17.924′ W; 147–148 m; 17–28 SeP. 2004; VERTIDOS AG-EBS-150 • 1 sh; Polygon delimited by Points 44° 10.000′ N, 009° 00.000′ W /44° 10.000′ N, 008° 35.000′ W/44° 00.000′ N; 009° 00.000′ W/44° 07.000′ N; 008° 35.000′ W; 417–668 m ; SARRIDAL (2006–07) SARRI-3.

Remarks. It is a common sublittoral NE Atlantic, usually from the intertidal zone to about 100 m depth, and rarely deeper (Fretter & Graham 1978; Nekhaev et al. 2014). Bouchet & Warén (1993) did not include it among the NE Atlantic bathyal species.

Only two empty shells and one fragment were found from two samples. One of the shells from 417–668 m was well preserved (Fig. 21f), which is surprising since O. semicostata is a shallow-water species.