EXCURSIONS ON THE COAST. 389 



lowing some concerted plan of action. They were descend- 

 ing the trunk of a large tree in a solid phalanx about two 

 handbreadths in width, and six or eight feet in length ; 

 no doubt coming down to make their chrysalids in the sand. 

 We returned to the steamer at ten o'clock ; and, after break- 

 fast, finding our anchorage-ground somewhat rough as the 

 tide came in, we went a little higher up, and entered the 

 Bahia do Sul. Here again we went on shore to see the 

 net drawn, this time more successfully. We should have 

 had a delightful walk on the beach again, had it not been 

 for hosts of minute flies which hovered about us, and had 

 a power of stinging quite disproportionate to their size. On 

 returning we met with an unforeseen difficulty. The tide 

 had been falling during our walk, and the canoe could 

 not approach the beach within several yards. The gentle- 

 men plunged in, and walked out over knees in water ; 

 while the boatmen made a chair of their arms and carried 

 me through the surf. 



March 5th. Our excursion in the harbor closed with 

 a visit to the small island of Tatuatuba, distant about 

 six miles from Para. In order to examine the shores, we 

 made the circuit of the island on foot. Here again the 

 same geological structure presented itself; and there was 

 one spot in particular where the sharp, vertical cut of the 

 bank facing the beach presented an admirable section of the 

 formations so characteristic of the Amazonian Yalley ; 

 the red, sandy clay of the upper deposit filling in all the 

 undulations and inequalities of the sandstone below, the 

 surface of which was remarkably irregular. The sea is 

 making great encroachments on the shore of this island. 

 Senhor Figueiredo, who lives here with his family and by 

 whom we were received with much hospitality, told us that 



