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coincides with the period of the lowest waters. 

 The Oroonoko beginning to increase from the 

 vernal equinox^ the lowest shores are found un- 

 covered from the end of January till the 20th or 

 25th of March. The arrau tortoises collected 

 in troops from the month of January, issue then 

 from the water, and warm themselves in the 

 Sun, reposing on the sands. The Indians be- 

 lieve, that a great heat is indispensable to the 



have made no mention of a proboscis; and, if I dared to 

 trust my memory, I should say, that the adult arrau is not 

 furnished with one like the matamata. We must not forget, 

 however, that the genus chelys has been formed from the 

 knowledge of one species only, and what belongs to the genus, 

 and what belongs to the species, may have been confounded. 

 The true characteristics of the new genus chelys are the form 

 of the mouth, and the membranous appendages of the chin 

 and neck. I never found in America the real testudo fim- 

 briata of Cayenne, the scales of which have a conic and py- 

 ramidal form j and I was the more surprised to see, that 

 Father Gili, missionary at Encaramada, three hundred and 

 twenty leagues from Cayenne, in a work published in 1788, 

 already distinguished the arrau and the terekay from a much 

 smaller tortoise, which he calls matamata. He gives it in his 

 Italian description, il guscio no convesso come nelle altre tarta- 

 rughe, ma piano, scabroso e deforme. These last characters very 

 well agree with the testudo fimbriata j and, as Father Gili 

 was acquainted neither with zoology, nor with, the books 

 that treat of this science, we may suppose, that he described 

 the matamata of the Oroonoko as he saw it. From these 

 researches it results, that three neighbouring species^ the 

 arrau, the terekay, and the testudo fimbriata, inhabit one and 

 the same region of the New Continent. 



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