236 Proceedings of the Royal Physical Socvety. 
Nassa incrassata (Strom.). 
Buccinum (Incrassatum), Strom., in Kong. Norsk. vid. Selsk. Skr., iv., 
p. 369, t. xvi., fig. 25. 
Nassa incrassata, F. and H., vol. iii., p. 391, pl. eviii., figs. 3 and 4. 
i e Jeff., loc, cit., vol. iv:, p. 354; vol. v., pl. Ixxxviii., 
fig. 1. 
Rare. These two species have been obtained in the 
Quaternary deposits, and appear to have a wide dis- 
tribution. 
In the living condition these species are of frequent occur- 
rence throughout the British Islands. 
Family PLEUROTOMATID. 
Pleurotoma, Pleurotoma nebula (Montagu). 
Lamarck. 
Murex nebula, Mont., Test. Brit. (i.), p. 267, t. 15, fig. 6. 
Mangelia nebula, F. and H., vol. iii., p. 476, pl. cxiv., fig. 7. 
Pleurotoma nebula, Jeff., loc. cit., vol. iv., p. 884; vol v., pl. xci., 
ae 
Rather rare. The fossil distribution of this species appears 
to be rather limited; in Scotland, at anyrate, the only previous 
record is Caithness. 
Pleurotoma septangularis (Montagu). 
Murex septangularis, Mont., Test. Brit. (i.), p. 260, t. 9, fig. 5. 
Mangelia (Bela) septangularis, F, and H., vol. iii, p. 458, pl. ext, 
figs. 6 and 7. 
Pleurotome septangularis, Jeff., loc. cit., vol. iv, p. 390; vol. v., pl. 
xci., fig. 5. 
Rare. This species has been obtained at Cocklemill Burn ; 
Elie; and is also recorded from the estuarine deposit at 
Belfast. 
In the living condition these two species appear to be 
generally distributed throughout the British Islands. 
