NATICA. 463 
proofs of the intimate connection between Janthina and Sca- 
laria, that they are the only two spiral animals which copiously 
emit the purple fluid. Many of the Murices produce the 
purple dye, but not until the gland is punctured, when a 
greenish-white fluid is obtained, which becomes purple on 
exposure to the air. 
S. communis, Lamarck. 
S. communis, Brit. Moll. iii. p. 206, pl. 70. f. 9, 10. 
S. Turtont, Turton. 
S. Turtoni, Brit. Moll. iii. p. 204, pl. 70. f. 1, 2. 
S. Gra@nianpica, Auct. 
S. Grenlandica, Brit. Moll. iii. p. 211, pl. 70. f. 5, 6. 
S. Trevitiiana, Leach. 
S. Trevilliana, Brit. Moll. iii. p. 213, pl. 70. f. 7, 8; (animal) pl. F.F. 
f. 1-3. 
The above have not been met with alive. We believe the 
S. Grenlandica is not British. 
NATICA, Bruguiere. 
This genus has several British species, and is one of the 
anomalies that are occasionally met with in every department 
of zoology, and which cannot enter into natural order in re- 
gular progression, but must be intercalated as excrescences, in 
line with the objects to which they have the greatest affinity. 
The present animal has alliances throughout the scale of its 
class. By the position of the eyes in the species that have 
them, and the peculiar character of the fiat tentacula coales- 
cing with the membrane of the head, it exhibits a connection 
with the Eulime and Chemnitzie ; it shows only shght con- 
nection by the operculum with the Littorine ; it has also by 
the foot a certaim affinity with the Bulle; but the important 
organ which fixes its true position is the retractile proboscis, 
the invariable concomitant of the Muricidal tribes, by which 
this apparently ambiguous animal becomes one of the poimts 
of transition from the Holostomata to the Canalifera, and I 
think that it ought to enter the natural order as a member 
of the new family. 
