314 ANNUAL OF SCIENTIFIC DISCOVERT. 



ZOOLOGY OF BRAZIL. 



The following information concerning the animals of Brazil is 

 condensed from the lectures of Prof. Agassiz befox'e the Lowell 

 Institute, Boston, Mass., in October, 18(jG. 



Fishes of the Amazon. — He allmled to the astonishing variety 

 of lishes found in the Amazon, very far surpassing wliat was 

 before known on the subject, and most astonishing in comparison 

 with other rivers. The Mississippi had yielded but one lunulrcd 

 varieties, and the rivers of thi' old worltl not so many, thougli of 

 larger size, lie is reported to have collected over eighteen linu- 

 dred varieties in the Amazon. The Amazon contained no cyprin- 

 idaj or suckers, no perch, no pickerel, no trout; l)ut goniodoiits 

 teemed in its waters, in many species. The; kinds varied in the 

 different jilaces in the valley, no two localities yielding the same 

 kind. They were also found in other rivers in Brazil, and even 

 north of that country in South America. They were to be found 

 in the nnid and in hollow trees in tin; water. One of the species 

 took care of its young as no other fish did, being provideil with 

 npron-like appendaj^es on the jaws, which extended along half 

 the length of the abdomen. On these they deposit their eggs, and 

 carry them altout until the young are hatched. Another kind 

 bored holes in the river bank, three or four feet in depth, and 

 dej)0sited their eggs therein in round bunches. 



The family of Callichlhijs, characterized by two rows of scales 

 upon their sides, with a depression between them, have the pecu- 

 liar habit of leaving the water at times, and he said he had fre- 

 quently found them on dry land three miles from the water. 

 They deposit their eggs in a cavity, after the manner of the stickle- 

 back, and hatch them by silting upon them. They will ascend 

 trees. 



The Dorades are mainly distinguished by a single row of scales 

 on each side, though some of the genera have two and three rows. 

 Another family, the Aspherides, lay their eggs and then pass over 

 them, the eggs becoming agglutinated to the under sides of their 

 bodies, and remaining held there by a filament until hatched. 



He desciibed several other families of this order, with their 

 peculiarities of form, color, and habits, remarking that several of 

 these families have liitherto been unknown to naturalists. The 

 Characvics represent in the tropic waters our salmon. The pecu- 

 liar construction of the mouth marks the different families of this 

 ci'der, some of them being entirely toothless, others having teeth 

 only in the upper jaw, and others having both jaws armed with 

 teeth. These families also differ so much in color that the com- 

 bination of lines seems almost endless, though there is a general 

 plan in the colors as much as in the form. One of these families 

 is a most formidable fish, having a wide mouth, armed on both 

 sides with pointed, serrated teeth. A horse or cow falling into 

 the river would be devoured in one hour by these greedy fish. 



He had a curiosity to ascertain how the marine scates compared 

 with the scates found in the rivers, and had made compai'iscjns as 

 he proceeded up the Para river. The first scate he ibund after 



