&4 Descriptions of British Chitones and other shells, 



that the present attempt to identify a few British speeies will, I 

 fear, on my part, appear not a little presumptuous. My object 

 will however be attained should I succeed in drawing to the sub- 

 ject the attention of some one better qualified than myself for 

 such an undertaking. 



Though considerable obscurity appears to extend in some mea- 

 sure over all the species of this intricate genus, the greatest con- 

 fusion exists amongst the British species. In some instances in- 

 deed, it has become almost impossible satisfactorily to reconcile 

 the discordant synonymes and more discordant descriptions by 

 various authors, of the same individual species. This, perhaps, 

 is not so much owing to the inaccuracy of the descriptions them- 

 selves, as to the insufficiency of those characters on which most 

 writers have grounded their specific distinctions. Great uncer- 

 tainty has also necessarily arisen from the deficiency of all the 

 hitherto published figures of the less striking species of this genus; 

 — an imperfection doubtless to be attributed to the difficulty of 

 expressing those minute but essentially important characters on 

 which alone the permanent specific distinctions of these shells 

 must rest. The figures in the work of Martini and Chemnitz, 

 are certainly as characteristic in habit of the shells they are in- 

 tended to represent as the nature of the work would authorise us 

 to expect : but any one will be ready to acknowledge their defi- 

 ciency in every particular of minute detail or delicacy of execu- 

 tion. 



As far as the British species are concerned, little more can be 

 said in favour of the figures in Wood, Pennant, Montague, the 

 Linna^an Transactions, &c. The only exception to these remarks 

 I have met with, is the figure of Chiton Icevis, in an unpublished 

 plate engraved for Leach's Brit. Mollus. This might indeed almost 

 serve as a model for future artists ; and in accuracy and delicacy 

 of delineation cannot perhaps be well exceeded. 



Under these circumstances, and without the opportunity of 

 comparing my species with authentic specimens of those hitherto 

 described as British in this intricate genus, I have found extreme 

 difficulty in reconciling the discrepancies, and arranging under 

 their proper types, the imperfect descriptions of different authors. 



