274 
SOUTH AMERICAN HIPPURITES 
D’Orbiguy,^ in 1847, figured a very imperfect specimen from the 
Cretacic rocks of Chile, which he called Hippurites (?), but it is 
so indefinite that it has not been considered by later students. 
The exact age of Hippurites holiviensis, or whether the contain¬ 
ing formation still outcrops along the eastern margin of the Bo¬ 
livian altaplanicie, is unknown. The form is evidently a Late 
Cretacic type, and probably is of the same age as Bchinocorys 
poznanskii, Berry, from the same general region. I regard both 
of these forms as contemporaneous with the maximum extension 
of the Late Cretacic sea in the Andean geosyncline, and about of 
the same age as the littoral and sub-continental Puca sandstone 
of eastern Bolivia. 
The genus Echinocorys appears, somewhat abruptly, in the 
European record during Turonian time, and although it may have, 
and probably did reach Europe from antecedent seas outside of 
Europe, the latter was obviously much nearer than was Bolivia 
to its center of evolution and dispersal. Hence the Bolivian oc¬ 
currence cannot well be older than Turonian. The genus Hip¬ 
purites is likewise characteristic of the Neo-Cretacic beds of the 
Mediterranean regions of the world and points in the same direc¬ 
tion as does Echinocorys. It may therefore be concluded that the 
geological age is not older than Turonian, and is probably young¬ 
er, namely either Emscherian or Campanian. 
4 Voy. dans I’Amer. Merid., tome viii, pi. 22, fig. 16, 1847. 
