CHAF. IV. THE AIITRiilS GENERAJXY. 127 



with Oliva must follow AnciUaria : in this way we 

 might go on until we have but one genus, Voluta. It is 

 only by thus following out such a theory of nomencla- 

 ture, that we see the full results to which it must, of 

 necessity, lead. We have, indeed, already spoken on 

 this subject ; but we think it desirable to place it more 

 esjiecially before our readers in this place, where the 

 opposite plan has been so prominently brought forward, 

 (117.) The whole of the Mitring, or Lamarckian 

 mitres, were considered but as one genus until about 

 twenty years ago, when we ventured to detach from 

 them a small group by the name of ConoeheUoc. Nearly 

 as great opposition was manifested to this innovation, 

 as has recently been made in respect to Cyprcecassis j 

 but this, of course, was to be expected from those 

 conchologists who looked only for " well-marked and 

 absolute divisions :" the group, however, was soon taken 

 up by the Continental naturalists, and is now generally 

 adopted. Having always had a peculiar fondness — 

 almost a passion — for these elegant shells, we continued 

 their study, until, in 1827^ our investigations had pro- 

 ceeded so far that we ventured to characterise the five 

 leading divisions, or genera. The great number of new 

 species discovered by Mr. Cummin, added to others con- 

 tinually coming before us, naturally led to a still more 

 close analysis of the whole. The result of this, in re- 

 gard to the theory of variation, was communicated to the 

 Zoological Society in 1835.* This theory is now found 

 to pervade the whole class of Testucea ; while, in our 

 Systematic Arrangement, will be found all the well- 

 known and clearly described species, distributed under 

 their several minor groups. The Mitrince, in comparison 

 to the volutes, with two or three exceptions, are much 

 smaller shells, chiefly distinguished by the smaller size 

 of the foot, as in Mitra episcopalis (Jig. 13.), where the 

 proboscis is excessively long ; and by the greater length 

 of their spire, the tip of which is never papillary. f The 



* Proceedings of the Zool. Society, part iii. p. 197 



+ Except in two or three species oi Mitreola, whicli blend into Harpvln. 



