TEREBELLA. 199 



transferred the specimen to a tall narrow jar, wherein the tube now con- 

 structed was carried up the side as a semi-cylinder, thus exposing every 

 thing satisfactorily to view. Sometimes, on attaining to a certain height, 

 the tube quitting the glass becomes a perfect cylinder, and is continued 

 in this shape, with the orifice directed towards the centre of the vessel. 



Two specimens of large size reached me from Shetland on June 29. 

 Both were mutilated at the posterior extremity, which prevented the de- 

 termination of its true form. But such as*it was is truly represented. 



The smaller of the specimens died in a week. The largest survived, 

 remaining vigorous, and displaying great activity. 



Regeneration of the defective extremity soon followed. In ten 

 weeks it consisted evidently of ten or twelve segments. Their number 

 and dimensions augmented, and in five months from the date of acquisi- 

 tion, the portion reproduced appeared as in Plate XXIX. fig. 2. It then 

 remained grey as from an early stage, but gradually darkening, and 

 becoming finely speckled throughout, an original characteristic of the 

 species was satisfactorily exhibited. 



The specimen survived at least ten months, having become some- 

 what darker with time. 



PLATE XXIX. 



FIG. J . Terebella tuber culata. 

 2. Regenerated extremity. 



PLATE XXVI. 



FIG. 8. Portion of one of the branchiae, enlarged. 



4. TEREBELLA CONCHILEGA The Shell-binder. Plate XXVIII. 

 Figs. 3, 4, 5, 6, 7, 8. 



Of the whole Terebellae inhabiting our seas, this species seems to 

 have misled naturalists the most. Transient inspection, and that of a very 

 insufficient and unsatisfactory kind, has been probably the means of con- 

 founding it with the species first described. But although the distinc- 



