404 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1908. 
mann, were found to be Neocomian (Wealdan) flora. The fauna - 
from San Lorenzo was also referred to the Neocomian. The fauna 
from Huallauca, Lucha, and Chaco was found to be Albien, with the 
Rotomagien (?) lower Cenomian also represented at Huallauca. The 
Santonien was determined at Abra de Charata (between Oroya and 
Tarma), and from Lucha and Huallauca and Le Quinua. The rich 
material described increased the number of Senonian fossils from 
Peru and contained some entirely new forms, while the Wealdan 
flora was the first found in South America. 
It will be remembered that Steinmann (1906) has referred to the 
Cretaceous the Puca sandstone formation, so named by him and 
which includes the Cora-Cora copper mines of Bolivia. This has 
already been discussed under the heading of the Permian. The Puca 
sandstone extends into Peru. 
TERTIARY. 
Marine Tertiary of the Pacific coast. 
The marine Tertiary of the southern coastal plains was described 
by Forbes (1860), who called it the “ Tertiary and diluvial formation 
of the coast.” This formation is also shown in the section by 
d’Orbigny (1842) and by Pissis (1856), who, however, did not de- 
vote much attention to it. According to Forbes the Tertiary extends 
inland from the stretch of low coast lying to the north of Arica, 
forming gently sloping plains which show evidence of ancient sea 
beaches. The plains are composed of sand, earth, and gravel, with 
abundant fragments of porphyritic rocks from the mountains to the 
east. Forbes mentions a trachytic volcanic formation seemingly con- 
temporaneous with the plains formation, which appears to have been 
deposited while they were still under water. This volcanic material 
is in the form of tuffs and ashes and has subsranenyy, been covered 
by other deposits. 
In discussing the saline deposits of the coastal abi (especially 
in territory that now is in Chile) Forbes advances the idea that with 
the exception of the boracic-acid compounds, the presence of which 
is due to volcanic causes, all the salines are such as would be left by 
evaporating sea water or by mutual reactions of saline matters thus 
left. This lacustrine hypothesis he applies to the nitrate deposits 
and states that the chain of hills to the west is such as might on 
elevation have inclosed a series of lagoons in tidal communication 
with the sea. For the saline deposits at high elevations he includes 
the factor of rainfall and states that they are not so characteristic of 
the lagoon type as the lower deposits near the coast. 
The next reference to the Tertiary of the coast is concerning the 
formations in the northern coastal plains. Among the fossils sent 
