Naticopsis (Naticopsis) osbornei Yoo

PI. 14 Figs 1-8

Naticopsis (Naticopsis) osbornei Yoo, 1988: 244, figs 65-66.

Additional material. 8 specimens from 'Marohn' (Locality 28) and 1 specimen from G1enbawn (Locality 30).

Geographic distribution. 'Rangari' to Glenbawn.

Geological age. Middle to late Tournaisian.

Remarks. Fifty specimens recovered between 'Rangari' and Glenbawn show a considerable variability in shell shape, ornamentation and callus rugae. Some forms are elongate while others seem distorted. The shape and size of callus are also variable. Specimens are usually ornamented by collabral striae which are more distinct in the last whorl. Plate 14 figure 6 shows stronger striae developed just below the suture of the last whorl.