COLLECTION OF FISH. 449 



habit our streams, the smaller stickleback, is not 

 one inch in length. The second is somewhat 

 larger, and the third comes from North America* 



The centronoti, Lacep., are allied to the gasie* 

 rostei. We have four species of them. The pilot 

 (g*. ductor y Liii.) belongs to this genus: it is so called 

 because it swims before the shark, and points 

 out its prey. We have fifteen species of the genus 

 zeus, Lin., which has been divided into three 

 sub-genera. The most common is the z.faberJLAxx., 

 fotfftd in the Ocean and the Mediterranean ; it is 

 of a yellow colour, with a black spot on each 

 side : the other species belong almost all to the 

 Indian seas. The genus lampris, Pvetz, has but 

 two species, very rare and remarkable for the 

 beauty of their colours. The first is the opah 

 (z. regius), which has been suspended to the 

 Oeiling on account of its size ; the other, as yet 

 undescribed, was presented by count Lynch, and 

 M. de Lacepede will soon publish it under the 

 name of z. argjropomus. The sword-fish {xy- 

 phias), remarkable for its sword-shaped snout, 

 which is sometimes 3 feet long. The specimen 

 in the gallery is xyphius gladius from the Medi- 

 terranean ; we have only the snout of the East 

 Indian species, the broad-finned sword-fish. 



The genus coryphcena, Lin., has been divi3ed 

 into four sub-genera, all in the collection, except 



2 9 







