FISHES OF GUIANA. 127 



some work where the generic characters were 

 given; while the great expense of such as have 

 appeared since his first expedition, would have ren- 

 dered them far from accessible, even if they could 

 have been forwarded in time. As that gentleman 

 has stated at the commencement of his Introduction, 

 no intention to publish his materials was contem- 

 plated, more particularly as few of the specimens 

 themselves had been brought to this country; yet 

 upon looking over his drawings and the accompany- 

 ing notes, so many curious forms presented them- 

 selves, different from those figured by Humboldt, 

 Spix, or in the later work of D'Orbigny, that it 

 seemed wrong to withhold them; while it would 

 also have concealed from the public the labours of 

 our traveller in this department, which, under the 

 circumstances, have been very considerable : our 

 views of the importance of the collection is also 

 borne out by the appearance of the fifteenth volume 

 of the work of M. Valenciennes, devoted to the 

 Silmidas and Loricarinae, — and even from this, con- 

 taining, it is to be presumed, the very latest infor- 

 mation, many of our Guiana species seem to be 

 wanting. The collection will be still more enhanced 

 in value, when it is known that it has been pro- 

 cured entirely from the fresh waters or from the 

 rivers, a considerable part of it at a distance of many 

 hundreds of miles from the sea, and in regions never 

 previously visited by the naturalist. We shall thus 

 be enabled to compare the forms with those in the 

 rivers of the other great divisions of the world ; not 



