1891.] Geology and Paleontology. 481 
rivers of Africa. The vertebrz in this genus are ossified and biconcave. 
The Podopterygia has also two orders. They are thus defined : 
Branchiostegal rays present ; Lysopteri. 
‘No branchiostegal rays ; Chondrostei. 
In these orders the notochord is persistent, and there are either 
actinotrichia, or fin-rays which are more numerous than the baseosts. 
Tail heterocercal or diphycercal. 
The location of the Lysopteri in the Podopterygia by Woodward is 
due to the discovery by Traquair of the characters of the pectoral and 
ventral fins, The order includes four families, which differ as follows : 
I. Tail heterocercal, 
Teeth acute, external ; Palaoniscide. 
Teeth obtuse, on palate and splenial ; Platysomide. 
No teeth ; Chondrosteida. 
II. Tail diphycercal. 
Teeth present ; scuta on body ; Belonorynchide. 
The Chondrostei include two families, the Accipenseride and the 
Polyodontide, both a which make their first appearance in the 
Eocene.—E. D. Cop 
Paleontology of Argentina.—A new journal devoted to natural 
history has just been established by M. Florentino Ameghino, at Buenos 
Ayres, under the title, Revista Argentina de Historia Naturel. Inthe 
Bulletin Bibliographic is given the titles of the memoirs in the first 
number. Among the notes will be found the following statements 
of especial interest to paleontologists : | 
Two scientific expeditions are now at work in Southern Patagonia. 
One, under the direction of M. Ramon Lista, governor of the territory 
of Santa Cruz, which has for its object the geography of the country, 
left the Island of Pavon November 5th, 1890, in order to explore the 
lakes of the Andes. The other exploration, which is exclusively geo- 
logical, under the direction of M. Carlos Ameghino, had for its object 
the study of geology, and to collect fossil remains in that region. The 
notes received up to this time (February, 1891) warrant us in stating 
that the results of this expedition surpass all preceding ones. 
Farther north, the oligocene formations in the vicinity of Parana 
were explored, during the year 1890, by MM. Scalabrini and Léon 
Lelong, who collected an immense quantity of bones of fossil verte- 
brates belonging to a type entirely unknown up to this time. A second 
formation of the same epoch, equally rich in fossil remains, has been 
discovered at Arroyo del Espinillo, about fifteen miles from the city 
of Parana. Many of the species are new to science. 
