84 INTRODUCTION. 



The number of fishes which thus were drawn 

 and described, during our expedition, amounted to 

 upwards of eighty, all of which were found in the 

 fresh waters. The late Mr. Hillhouse, in his " In- 

 dian Notices," enumerates twenty-six species as 

 peculiar to the coast, estuaries, and rivers of Gui- 

 ana. How incomplete this enumeration was, is 

 shown by the number which have been secured 

 during our expedition, in the rivers of the interior 

 alone; and I consider my own list so incomplete, 

 that in my pending expedition I hope to collect 

 materials sufficient for a second volume, in which 

 will be included the fishes of the estuaries and 

 coast also. 



The scientific world has much to regret that the 

 interesting researches of Dr. Hancock in Guiana 

 are intended to remain a hidden treasure. His long 

 sojourn in those regions, and his scientific acquire- 

 ments, would have rendered him particularly quali- 

 fied to become an illustrator of the natural history 

 of Guiana. But it appears that his researches are 

 only intended for his personal gratification, and with 

 the exception of a few detached papers printed in 

 some of the scientific periodicals, we cannot pride 

 ourselves of having profited much by his long ex- 

 perience and researches in South America. 



From these preliminary remarks, let us turn now 

 to those regions which have been lately visited by 

 me, and which become of interest as the locality of 

 the fishes, a description of which is to occupy the 

 present volume. 



