VOYAGE FROM NEW YORK TO RIO DE JANEIRO. 27 
yet wo have had no intensely warm weather. The sun, 
however, keeps us within doors a great part of the day, 
but in the evening we sit on the guards, watch the sunset 
over the waters, and then the moonlight, and so while away 
the time till nine or ten o'clock, when one by one the party 
disperses. The sea has been so rough that we have not 
been able to capture anything, but when we get into 
smoother waters, our naturalists will be on the look out 
for jelly-fish, argonautas, and the like. 
April 13f7i. In to-day's lecture Mr. Agassiz returned 
again to the subject of geographical distribution and the 
importance of localizing the collections with great precision. 
" As Rio de Janeiro is our starting-point, the water-system 
in its immediate neighborhood will be as it were a school- 
room for us during the first week of our Brazilian life. 
"We shall not find it so easy a matter as it seems to keep 
our collections distinct in this region. The head-waters of 
some of the rivers near Rio, flowing in opposite directions, 
are in such close proximity that it will be difficult sometimes 
to distinguish them. Outside of the coast range, to which the 
Organ Mountains belong, are a number of short streams, littlo 
rills, so to speak, emptying directly into the ocean. It will 
be important to ascertain whether the same animals occur 
in all these short water-courses. I think this will be found 
to be the case, because it is so with corresponding small 
rivers on our northern coast. There are little rivers along 
the whole coast from Maine to New Jersey ; all these dis- 
connected rivers contain a similar fauna. There is another 
extensive range inland of the coast ridge, the Serra de 
Mautiquera, sloping gently down to the ocean south of the 
Rio Belmonte or Jequitinhonha. Rivers arising in this 
range are more complex ; they have iarge tributaries. 
