64 
room viii. Pirena : of the second, Valvata, Paludina and 
Nat. hist. Ampullaria: of the third, Navicella, Neritina, 
Nerita, and 
(Table 21.) Natica. The families Ian- 
thinea, Macrostomata, Plicacea, Scalariana, and 
part of the Turbinacea, are also in this compart¬ 
ment. The first has but one genus, Ianthina : 
the second, the genera Sigaretus, Stomatella, 
Stomatia, Haliotis: the third, Tornatelia, 
Pyramidella; the fourth, Vermetus, Scalaria, 
Delphinula : the fifth, Solarium, Rotella, Tro- 
chus, 
(Table 22.) Monodonta, Turbo, Planaxis, 
Phasianella, and Turritella. Amongst the sca¬ 
laria, is the costly and beautiful shell S. pre- 
tiosa (Turbo scalaris. Lin.), or Wendel trap. 
The first genus of the family of the Canalifera, 
Cerithium is also in this compartment. 
(Table 23 ) Genera of the Canalifera con¬ 
tinued, viz.—Pleurotoma, Turbinella, Cancel- 
laria, Fasciolaria, Fusus, Pyrula, Struthiolaria, 
Ranella, Murex, and 
(Table 24.) Triton, the last genus of this fa¬ 
mily. In this compartment are also the genera 
of the family Alata, viz.—Rostellaria, Pterocera, 
and 'S trombus. 
(Tabee 25.) Part of the family Purpurifera, 
viz.—the genera, Cassidaria, Cassis, Ricinula, 
Purpura, Monoceros, Concholepas, Harpa, Do- 
lium, and part of the genus Buccinum. From 
the molluscous animal, inhabiting the purpura, 
the ancients obtained their celebrated purple 
dye, 
