APPENDIX. 537 







4 



From fanuaria Mr. St. John followed the San Francisco to the 

 Villa do Barra, where he made a short stay, and then resumed 

 his journey by land through the valley of the Rio Grande to the 

 Villa da Santa Rita, thence to Mocambo and across the table-land 

 separating the basin of the Rio San Francisco from that of the Rio 

 Paranahyba. At Paranagua he remained several days, and made 

 a considerable collection from this vicinity. Thence he followed 

 the valley of the Rio Gurugueia to Manga, one hundred and twenty 

 leagues from Paranagua. At Manga lie embarked on one of the 

 singular river-boats made of the leafstalks of the Buriti palm, and 

 descended the Paranahyba to the villa of San Gongallo. Here he 

 stayed for some time to collect, and forwarded from this vicinity a 

 considerable number of specimens, chiefly reptiles, birds, and insects. 

 His next station was at Therezina, the capital of the province of 

 Piauhy, where he made one of the most interesting collections of 

 the whole journey from the waters of the Rio Poty. The Poty is a 

 tributary of the Paranahyba, into which it empties below Therezina. 

 In examining this collection, I was particularly struck with the gen- 

 eral similarity of the fishes contained in it to those of the Amazons. 

 They exhibit throughout the same kind of combination of genera 

 and families, although the species are entirely distinct. Thus, from 

 a zoological point of view, the basin of the Parahyba, though com- 

 pletely separated from it by the ocean, would seem to belong to the 

 Amazonian basin, as it unquestionably does from a geological point 

 of view. The character of the drift deposits along the Rio Guru- 

 gueia and the Rio Paranahyba shows this area to have been con- 

 tinuous with the basin in which the Amazonian drift was deposited ; 

 and the similarity of their zoological features is but another evi- 

 dence, from an entirely different source, of the extensive denudations 

 which have isolated these regions from one another by removing 

 the tracts which formerly made them a unit. 



From Therezina Mr. St. John proceeded to Caxias, and finally 

 arrived in Maranham, by the way of the Rio Itapicuni, on the 8th 

 January, 1866; having completed a journey of moie than seven 



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