2 ENGLAND TO RIO DE JANEIRO CHAP, i 



long and one thick, with a hollow passing quite through it ; 

 on one end was a brown spot, which might be the stomach 

 of the animal. Four of these, the whole number that we 

 took, adhered together when taken by their sides ; so that 

 at first we imagined them to be one animal : but upon being 

 put into a glass of water, they very soon separated, and 

 swam briskly about. 



31 st. Observed about the ship several of the birds called 

 by the seamen Mother Carey's Chickens, Procellaria pelagica, 

 Linn., which were thought by them to be a sure presage of 

 a storm, as indeed it proved. 



2nd September. The casting-net brought up two kinds of 

 animals, different from any before taken. They came up in 

 clusters, both sorts indifferently in each cluster, although 

 there were much fewer of a horned kind than of the other : 

 they seemed to be two species of one genus, but are not at 

 all reducible to any hitherto described. 



3rd. We were employed all day in describing the 

 animals taken yesterday : we found them to be of a new 

 genus, and of the same as that taken on the 28th of August ; 

 we called the genus Dagysa, from the likeness of one species 

 to a gem. 



4th. Employed in fishing with the casting -net. We 

 were fortunate in taking several specimens of Dagysa saccata 

 adhering together, sometimes to the length of a yard or 

 more, and shining in the water with very beautiful colours ; 

 but another insect we took to-day was possessed of more 

 beautiful colouring than anything in nature I have ever seen, 

 hardly excepting gems. It is of a new genus, called Carcinium, 

 of which we took another species, having no beauty to boast 

 of ; but the first, which we called opalinum, shone in the water 

 with all the splendour and variety of colours that we observe 

 in a real opal. It lived in a glass of salt water, in which it 

 was put for examination, several hours, darting about with 

 great agility, and at every motion showing an almost infinite 

 variety of changeable colours. Towards the evening of this 

 day a new phenomenon appeared : the sea was almost 

 covered with a small species of crab (Cancer depurator, Linn.), 



