698 ANABLEPS. 



that in some species, at least, the whole process of develop- 

 ment is begun and completed in the gill cavity. 



The species which lay their eggs in the sand belong to the 

 genera Hydrogonus and Choetobranchus. They build a kind 

 of flat nest in the sand or mud, in which they deposit their 

 eggs, hovering over them until the young are hatched. 



Curious also is the little bill-fish — the lymnobellus- with 

 its long beak. 



Another fish (the anojas), common in the Amazon, takes 

 shelter — for it cannot be said to build a nest — in a hollow loir. 

 It belongs to the genus Auchenipterus. Numbers of this fish 

 are found crowded in dead logs at the bottom of the river. 

 One examined by the Professor, was filled with fish of all 

 sizes, from those several inches long to the tiniest young. The 

 fish were so dexterously packed into the log from one end to 

 the other, that it was impossible to get them out without 

 splitting it open, when they were all found alive and in a 

 perfectly good condition. They could not have been jammed 

 artificially into the hollow wood in that way without injuring 

 them. 



ANABLEPS. 



We have heard of blind fish, but here is <>nc called by the 

 Indians tralhote, and known to naturalists as the Anableps 

 tetraophthalmus, signifying "four-eyed" possessing four eyes. 

 A membraneous fold, enclosing the bulb of the eye, stretches 

 across the pupil, dividing the visual apparatus into the upper 

 and lower half; a curious formation, suited to the peculiar 

 habits of the anableps. These fishes gather in shoals on the 

 surface of the water, their heads resting partly above and partly 

 below the surface, and they move by a leaping motion some- 

 what like that of frogs on land. Thus, half in and half out 



