his Voyage to South America. 445 



has pointed out to me that in the narrative of the voyage of 

 the Nassau fleet, undertaken in 1623, as given in Binnej's 

 Voyages, vol. iii. p. 9), it is recorded that on the 19th and 

 20th of January, 1624, when the fleet was ofl" the coast of 

 South America in lat. 42° 15' S., " the sea near them was in 

 many parts discoloured with an infinite number of small red 

 shrimps." On our return to the Strait, we continued our 

 operations till the middle of June, when the increasing seve- 

 rity of the weather caused us to move northwards for winter- 

 quarters. We reached Rio de Janeiro on the 1st of July, and 

 remained there for three months and a half. I need not des- 

 cant on the glorious scenery or the wonderful profusion of 

 animal- and plant-life in that magnificent country; for that, I 

 presume, is well known to you. I could not afford time for 

 any very long journeys, but went far enough to see the 

 virgin forests in all their glory. I paid two visits to the house 

 of a most hospitable Scotchman who lives on the Serra do 

 Mar, about fifty miles from Rio ; and I spent a few days at 

 Tijuca, about ten miles from the city, where I saw the most 

 wonderful exhibition of boulders that it has ever been my 

 lot to witness. 



The mention of Tijuca reminds me of a matter that I 

 shall feel much obliged to you if you can give me a 

 little information upon, viz. how far is the development 

 of the land and freshwater decapods made out? I am 

 aware that the crayfish is stated not to undergo any meta- 

 morphosis in the young state ; but I have not been able to 

 ascertain, in the limited number of books which I have here 

 for considtation, whether the same thing holds good in the 

 Brachyurous Decapoda. I obtained several specimens of a 

 crab, in the province of Rio de Janeiro, which frequents 

 streams and damp rocks in their vicinity ; and while exploring 

 the banks of a cascade in the neighbourhood of Tijuca, I ob- 

 tained a female specimen, which, to my surprise, had between 

 fifty and sixty fully developed live young ones under the 

 pleon, in the ordinary position of the ova. These little crea- 

 tures were very active, and several escaped on the parent 

 being captured ; but I have preserved a number of them, and 

 I send you specimens in this letter, together with a careful 

 sketch of the parent. This occurrence, it appears to me, goes 

 far to prove that this species either undergoes no marked 

 metamorphosis between the egg and the perfect animal, or 

 else that the metamorphosis takes place while the young ani- 

 mal is beneath the pleon of its parent. The body of the adult 

 crab is of a dull purple colour ; the legs are of a considerably 

 paler tint. [App., VII.; PI. XXL fig. 3.] 



