28 o 
PATAGONIAN EXPEDITIONS I PALAEONTOLOGY. 
Punta Arenas , horizon V (uppermost). See the description of the 
Punta Arenas section, given by the writer, according to Hatcher’s observa- 
tions, 1898, p. 481. 
Ameghino (1899, p. 13) has completely misunderstood, and arbitrarily 
changed the account the writer has given of this horizon. Hatcher 
labelled some oysters collected here: “below” and “above” V. This 
means only that this horizon begins, at the base, with an almost solid 
layer of oysters, then follows a layer of dark-greenish sand that contains 
the other fossils, which ends again, at the top, in a similar layer of oyster 
shells. This whole horizon, including both oyster beds, is a unit, and 
there is no break at all. Nevertheless, Ameghino constructs an hiatus 
between the upper oyster layer and the rest, and correlates the former 
with his Tehuelche formation, the latter with the Suprapatagonian part of 
the Santacruzian formation. This assumption of an hiatus within our 
horizon V is entirely unwarranted, and characterizes Ameghino’s manner 
of trimming facts to suit his theories, even without having seen the origi- 
nal locality. 
We must take together all the fossils found here, and may mention only 
that Ostrea ingens occurs everywhere in this horizon (also in the sand be- 
tween the two oyster beds), and that Sigapatella has been found only in- 
side of oyster shells of the upper oyster bed. The latter consists of a 
form of Ostrea ingens , that resembles much the Cape Fairweather variety : 
* Glycimeris ibaria. Venus chiloensis . * Sigapatella americana . 
L & S * Ostrea ingens. S Meretrix iheringi. 
A * Lucina promaucana . * Crepidula gregaria. 
Although very small, this list contains 5 species that are found at the 
type-locality at Santa Cruz (marked *). For the rest, so-called “Supra- 
patagonian” species prevail. Ostrea ingens is a Patagonian (Leonense) 
and Suprapatagonian species, and it is to be remarked, that the form 
hatcheri , which is said to be characteristic of the Leonense beds, has also 
been found here. 
In conclusion, I add here a list of those species which have been ascer- 
tained to be present both near the base and near the top of the Patagonian 
series (as understood by us). 
1 . Cidaris antarctica. 
I 
base : San Julian. 
top : 30 miles north of Rio Chalia. 
