127 



lias Ednsa. Some moths and Hymenoptera and a Calosoma accom- 

 panied the butterflies. — Id. 



7. Crab living on Cocoa-nuts. A crab (Birgos Latro?) lives on the 

 cocoa-nuts ; it is very common on all parts of the dry land in Keeling 

 Isle, and grows to a monstrous size. This crab has its front pair of 

 legs terminated by very strong and heavy pincers, and the last pair by 

 others which are narrow and weak. It begins by tearing the husk, 

 fibre by fibre, and always from that end under which the tlu-ee eye- 

 holes are situated ; and when this is completed, the crab commences 

 hammering with its heavy claws on one of the eye-holes, till an open- 

 ing is made ; then turning round its body by the aid of its posterior 

 and narrow pair of pincers, it extracts the white albuminous substance. 

 I think this is as curious a case of instinct as ever I heard of, and like- 

 wise of adaptation in structure between two objects apparently so 

 remote firom each other in the scheme of nature as a crab and a cocoa- 

 nut tree. The crabs inhabit deep burrows which they excavate beneath 

 the roots of trees, and here they accumulate quantities of the fibres of 

 the cocoa-nut husk, on which they rest as on a bed. — Id. 



8. Gossamer Sjnder. On its first arrival on the ship, about sixty 

 miles fi'om land, it appeared very thirsty, and with exserted maxillae 

 drank eagerly of water ; may it not be in consequence of its having 

 passed through a dry and rarified atmosphere ? Though quite calm, 

 the atmosphere can never be so tranquil as not to affect a vane so deli- 

 cate as the thread of a spider's web ; and the effect of an ascending cur- 

 rent of heated air would probably be sufficient to carry with it so light 

 an object as the little spider on its thread. Virey's observations ('Bull, 

 des Sci. Nat.' xix. 130) seem to prove that small spiders, in an atmo- 

 sphere perfectly tranquil, and without the aid of any web, have the 

 power of darting through the air. He believes that by means of a ra- 

 pid vibration of their feet, they walk the air ; but in other easels we 

 must suppose that the several threads which were sent forth, served as 

 sails for the atmospheric ciu'rents to act on. It appears to me far from 

 improbable that the little aeronaut actually did unite, as I suspected, 

 its feet together by some fine lines, thus forming artificial wings. — Id. 



9. Aphis Sonchi. Found underground in clusters on the roots of 

 the sow-thistle, in September and October. It appears again in 

 March, and equally infests young and full-grown plants. The insects 

 observed were pale green, covered with white pubescence, and had no 

 wings. — Francis Walker; Sonthgate, May ^, 1841. 



10. Aphis Dauci. Found in October undergromid, on the roots of 

 the carrot. Its colour was pale yellow, and it also had no wings, — /(/. 



