36 
131. 
133. 
134. 
THE MOLLUSCA OF DORSETSHIRE. 
PURPURIDA. 
PURPURA, Brug., 1789. 
P. lapillus (Z.) 
Pulteney, p. 44, pl. 15, f. 1-4, 9, 12. 
This is the true dog-periwinkle, very predaceous, and caa 
perforate the shell of its victim by the rasping action of its 
lingual ribbon. 
Common all round our coasts; extremely large on the rocks 
of Broad Bench, Kimmneridge Bay, J. C. M.-P. 
Fossil : Red Crag; raised beach, Portiand, Prestwich. 
NASSIDZA. 
NASSA, Lamarck, 1799. 
Most of the species are littoral. 
2. N. reticulata (Z.) 
Pulteney, p. 45, pl. 15, f. 10. 
Ranges from the edge of the Littoral to the upper part of the 
Laminarian zone. 
Very destructive to oysters, upon which it feeds, sometimes 
piercing as many as 15 or 20 in succession before its 
hunger is satisfied. 
N. inerassata (Strdm). 
Pulteney, p. 45, pl. 15, f. 8. 
Generally distributed round the coast. 
Swanage, J. E. Cooper, Aliss Cohon. 
Kimmeridge Bay, dredged (abundant), J. C. A-P. 
Fossil : Coralline and Red Crags. 
N. pygmea (Lamarck). 
Forbes and Hanley, Vol. iii., p. 394, pl. 108, f. 5, 6. 
Weymouth, dredged, abundant, S. Hanley, W. Thompson, 
E. R. Sykes. 
Kimmeridge Bay, Gadcliff, on sandy ground, dredged, 
J.C. M.-P. 
