ANALYTICAL INDEX. 



347 



CHAPTER VIII. continued. 



Tho nomenclature of Lamarck, Gmelin, and others defective, PAGE 182 



The Terebella and Amphitrite, . . . . 183 



1. TEREBELLA LITTORALIS, SEU ARENARIA, The Sand Mason, . ib. 



Its dwellings between half-tide and low-water mark, . ib. 

 Form, organs, &c., ...... 184 



Different species identified by the branchiae, . . ib. 



Branchiae so complex and luxuriant as to be indescribable, . ib. 



All of an arborescent form, . . . . 185 



Swims by violent contortions, . ib. 



The process of building described, . 186 



Flexibility and use of the tentacula, . . ib. 



Never resumes a tube if once forsaken, . 187 



Length of tube indefinite, . . ib. 

 Tubes directed horizontally, 



Fashion of the architect, . . ib. 



The animal can reverse itself in the tube, 189 



In the natural state a tuft terminates both ends of the tube, . ib. 



Use of these tufts uncertain, . . ib. 

 The extent of the animal's instinctive faculties may be ascertained 



by experiment, . . 



Food not ascertained, . . ib. 



Subject to mutilation, ..... ib. 



The Terebella, in dying, quits its tube, 191 



Plate XXVI. explained, . ib. 



2. TEREBELLA FIGULUS, The Potter, . ib. 

 In figure and habits resembles the preceding, 



Instinctively know they should be guarded from danger, . ib. 



Length, thickness, organs, &c., . ib. 

 Perhaps enjoys the reproductive faculties, 



Attempts at minute distinctions have led to fallacies, . ib. 

 The number of tentacula dependent on age, or they may denote 



distinctions not yet recognised, 



In fabricating its dwelling prefers mud, . ib. 



Deprived of its tube, the body is closely coiled up, ib. 



Never satisfied with the size of the tube, . 195 



Process of building, ..... ib. 



Size and form of the tube, . . 196 



Operations conducted so as to economise labour, . ib. 



The sense of feeling seems the strongest, . 197 



Vision most obscure, .... ib. 



