Rev. L. Gurlding's Mollusca Caribbcecma. 439 



lail too great an expense upon the Conductors of this admirable 

 Journal. The late addition of Supplementary Plates is a step 

 which every one must highly applaud, and which will tend to 

 render the work of the greatest possible service to the cause in 

 which we are engaged. 



I may here be permitted to notice a remark in the first volume 

 of the Journal, page 563, on my distribution of the genus OncJii- 

 dium. It is too true that the arrangement of the learned Dr. 

 Blainville has never reached my place of exile, and that I have 

 in this, as in many other instances been deprived of the advantages 

 of gleaning from the labours of other men, by the vast distance by 

 which I am separated from more civilized Europe, and all inter- 

 course with the sciences. How many allowances should be made 

 for the Naturalist doomed to reside a thousand leagues from every 

 place of learning, where no works can ever reach him, but such 

 as a moderate income can procure, to satisfy his thirst for in- 

 formation ! I must here request that, with the exception of the 

 drawings, every thing I may send to England on subjects of 

 Natural History, may be examined with the greatest caution and 

 suspicion. It must be remembered that without any fellow- 

 labourer to guide or to instruct innumerable errors may occur. 



I cannot agree with the Conductors of the Journal, in the 

 manner in which they would distribute the Onchidia. There can 

 be no doubt that the generic term must, in our advanced know- 

 ledge of these animals, be restricted to those species which most 

 nearly resemble in their economy and structure, O. Tijphce^ the 

 type of this curious genus, and which with 0. Sloanii, and 0. OC" 

 cidcntcde is not known to approach the water. " Semi-aquatic, 

 fresh-water, or maritime species," it will doubtless be found ne- 

 cessary to place under other genera. 



St. Vincent's, October 24tli, 1823. 



