248 NATURAL HISTORY OF 



and, on becoming alarmed at our approach, scuttled down to 

 the sea. I do not know whether, by reason of their 

 projecting eyes, they are more long-sighted than ordinary 

 crabs are, or whether their auditory sense is very acute, but 

 we were surprised to observe many of them begin to run 

 down to the w^ater when we were as much as twenty yards off. 

 They raised themselves very high on their legs, and ran with 

 such rapidity that we found it impossible to overtake them, 

 even running at full speed, as they dashed boldly into the 

 surf, whither we could not follow them. One, apparently 

 less wide-awake than the others, was at last captured by 

 our getting between it and the sea and surrounding it. This 

 individual was consigned to a small tin vasculum, and that 

 evening, being tired with my exertions, I went to bed without 

 removing it from its prison. It contrived, however, to make 

 such a racket as rendered sleep impossible, so that at last I 

 was obliged to get up and put an end to its existence by 

 immersing it in spirit. 



On the 1st of October I crossed to the opposite side of 

 the harbour, and walked round part of Five-fathom Bay. 

 iN'ear the shore, several very curious rocky pinnacles, some of 

 which bore a scanty vegetation on their summits, rise out of 

 the water. On the sandy beach I disturbed two black vultures 

 feeding on the putrefying carcass of a lamb. These birds, 

 the Gallinazo {Catliartes atratus), are very common about 

 Eio, where hundreds may be seen in the neighbourhood of 

 slaughter-houses at San Cristoval, perched on palings or the 

 branches of trees, on the look-out for offal. They may be 

 also observed soaring in circles at a great height in the air, 

 with the tips of the primary feathers widely separated. Mr. 

 Darwin remarks that he believes that this species, which has 

 a wide distribution in the northern parts of South America, 

 never extends to the south of the Eio JSTegro, in lat. 41°, and 



