NATICA. 463 



proofs of the intimate connection between lanthina and Sea- 

 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, pi. 70. f. 9, 10. 

 S. TURTONI, Turton. 



S. Turtoni, Brit. Moll. iii. p. 204, pi. 70. f. 1, 2. 



S. GRCENLANDICA, Auct. 



S. Grcenlandica, Brit. Moll. iii. p. 211, pi. 70. f. 5, 6. 

 S. TREVILLIANA, Leach. 



S. Trevilliana, Brit. Moll. iii. p. 213, pi. 70. f. 7, 8 ; (animal) pi. F.F. 

 f. 1-3. 



The above have not been met with alive. We believe the 

 S. Grcenlandica 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 flat tentacula coales- 

 cing with the membrane of the head, it exhibits a connection 

 with the Eulimae and Chemnitzia j it shows only slight con- 

 nection by the operculum with the Littorime j it has also by 

 the foot a certain affinity with the Bullte ; 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 points 

 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. 



