Vill INTRODUCTION. 
they amount to five-sixths of the whole. The Clupeide are an exception, in which 
all the species are apparently new. 
All the species described, belonging to the three families above mentioned, in 
which there are so many new, viz. the Siluride, the Cyprinide, and Salmonide, 
are from South America, and the Falkland Islands, excepting one from New 
Zealand. 
Of the remaining fresh-water fishes in the collection, three out of five are 
presumed to be new. One of these is a species of Perca, from the Santa Cruz 
river, in South Patagonia; the second is a species of Dules, from the river 
Matavai, in Tahiti; the third a species of Atherina, from Valparaiso. Perhaps, 
however, this last is not strictly an inland species. 
The entire number of fresh-water species in the collection is twenty-three, 
and the entire number of new ones amongst these is eighteen. The large 
proportion of these latter is a circumstance in confirmation of a remark which 
Cuvier has somewhere made, that the fresh-water fishes of foreign countries are 
much less known and understood than those found on the coasts. It may serve 
also as a hint to future travellers. 
The seven new genera in the collection belong—one to the Scienide, from 
the Galapagos Archipelago ;—one to the Scombride, from North Patagonia ;— 
three to the Blennide, whereof one is from the Archipelago of Chiloe, the second 
from the Falkland Islands, and the third from New Zealand ;—one to the Cy- 
prinide, embracing three species, from South Patagonia, Tierra del Fuego, and 
New Zealand ; and, lastly, one to the Salmonide, embracing two species from the 
Falkland Islands and Tierra del Fuego respectively. 
It has been already mentioned, that all the species obtained by Mr. Darwin 
in the Galapagos Archipelago have been preserved. As they are likewise all 
new, and those islands appear to have been scarcely visited by any naturalist 
previously, it may be interesting to enumerate the several genera to which they 
belong, and the number of species in each genus respectively. 
SERRANUS .... 3 species. Fam. PERCID. >| 
Prionotus .... 1 , —— TRIGLIDA. | 
Scorp#zna .... 1 ,, — SCORPANID. 
Prionopes V.G. 1 ,, ) | 
PristrpoMA.... 1 ,, ~—— SCIANIDE. S ACANTHOPTERYGII. 
WATINUS) vlstetciee 53 ) 
Curysopurys .. 1 ,, —— SPARIDE. | 
Gosius ...... ity ep — GOBIDZ. | 
Gossyenus) 2... 1! 5; — LABRIDA. J 
Gosrkrsox «... 2 ,, — CYCLOPTERIDA. 
Murmnaccs.... 1 — ANGUILLID. } Le OUP IEEE 
(LETRODON) «2.22 455 — TETRODONTIDZ. PLECTOGNATHI. 
