Report of the Voyage of the Coquille. 363 
Geological Collection*. 
This collection we owe to the care and researches of M. 
Lesson. It is composed of only 330 specimens; but these 
specimens have been collected with judgement, and from all 
the countries which the corvette visited. They are besides 
of a fine size, and perfectly characterized. 
Twelve of these specimens collected in the neighbourhood 
of Saint Catherine, on the coast of Brazil, show that this part 
of the American continent belongs to the ordinary granite 
formations. Thirty-three specimens from the Malouine Isles 
show that these isles belong to the oldest intermediate forma- 
tions. M. Lesson found there only phyllades, quartzose sand- 
stones, and grau-wackés, rarely furnishing some organic im- 
pressions similar to those known elsewhere. Twenty speci- 
mens were collected in the environs of Conception, on the 
coast of Chili. Some of them, from the peninsula of Talcagu- 
ana, are of phylladiform talcose rocks, and consequently be- 
long to the most recent primordial districts. The others, col- 
lected on the continent, present ordinary granitic rocks, and 
besides, true stratiform lignite, which at first sight might be 
taken for pit-coal. This lignite is dug at Penco; its existence 
may lead us to presume that there is at this point a portion of 
a tertiary formation of some extent. Two specimens of grayish 
phtanite were picked up near Lima; they prove the prolonga- 
tion of the talcose phylladiform districts in this part of the 
coast of Peru. 
The environs of Payta, on the same coast, have furnished 
fifty-two very varied specimens. They are: 1. talcose phylladi- 
form rocks, of which, according to M. Lesson’s account, the 
whole country consists, which consequently belongs to the 
primordial epoch; 2. clays, freestone, and calcaires grossiers, 
which compose a considerable district in which the strata are 
horizontal. This vast tertiary outlier is placed on talcose rocks 
150 feet above the level of the sea; its thickness is 72 feet in 
the escarpments which M. Lesson visited. Sandy clays tra- 
versed by small veins of fibrous gypsum and quartzose sand- 
stones compose the inferior beds. Numerous varieties of cal- 
caire grossier form the upper layers. ‘These varieties present 
most remarkable analogies with several of the varieties of the 
same rock of the environs of Paris. Their discovery is as cu- 
rious as it is important. 
Twenty-five specimens were brought from two of the So- 
ciety Isiands, namely, Otaheite and Borabora. All the speci- 
mens from Otaheite are basaltic lavas well characterized, and 
not ancient. So for the most part are those of Borabora; the 
others present a beautiful variety of dolerite. 
* This article is by M. Cordier, 
2272 The 
