142 CATALOGUE OF FISH. 



and is recovered during repose and by nourishing food. The organ 

 by \Yhich this wondrous power is manifested, extends along the 

 whole under side of the tail, of which it constitutes nearly the half 

 of its thickness. It is divisible into four longitudinal bundles, two 

 thicker upper ones, and two more slender below, approached to 

 the base of the anal fin. Each bundle consists of a multitude of 

 parallel membranes, and of nearly horizontal disks, approaching 

 very closely to each other. One side of the bundle is pressed 

 against the skin, and the other abuts on the mesial vertical plane 

 of the fish. Lastly, they are connected to one another by an 

 innumerable multitude of small transverse and vertical disks. The 

 small cells, or rather prismatic transverse canals, by which these 

 two kinds of disks are separated, are filled with a gelatinous matter, 

 and the whole apparatus is supplied with a proportionally great 

 number of nerves. (Cinner.) 



Two living examples were brought to London in the year 1842, 

 neither of them weighing more than one pound. In the year 1848 

 one of them had attained the weight of 40, and the other of 50 

 pounds, so that each of them had nearly doubled its weight in 

 every succeeding year. [Zoologist, No. 78, 1848. j The species, 

 its mode of capture, and many particulars of its natural history, are 

 given in Humboldt's Observations de Zoologie, p. 497. 



G. Mquilabiatus, described in page 46 of that work, and figured 

 on table x., requires to be still better described and figured before 

 w^e can venture to assign to it its proper place in the system. The 

 authors of the liorm Ichthijologicm place it at the end of their genus 

 Sternopijgiis ; and Humboldt figures it as destitute of scales, and 

 makes no mention of scales in his description, but says, " cidtratum, 

 nudum, muco obductum ;" hence it cannot be a Sternopygus. Of 

 the anal fin, the Baron also says, " sed ante caudam desinens, 

 radiis quinque." What do these five rays import? Probably an 

 error omitted in the previous enumeration. The distinction of 

 this species from electricus, by its swim-bladder, is also an error, 

 since both have a small heart-shaped, as well as a long swim- 

 bladder. Humboldt has overlooked the hinder bladder in ceqidla- 

 biatus, and the fore one in electricus. The last one is known to 

 be closed, and we may, from analogy, conclude the first to be so 

 also. 



It would be most interesting to catch this species in the river 

 Magdalena of New Granada, since it does not exist in any European 

 museum. It has a green colour and a silvery-white belly, with 

 small violet points ; the upper and lower colours being separated 

 by a longitudinal white stripe. Jaws of equal length. 



I 



