I also indicated the location of the Santa Cruz (?) plant locality at Mirhoja in Chubut area. Terminal sinus widest and deepest, extending three-quarters of the distance to the base of the lamina,. Venation dichotomous, diverging as a double dichotomy in the descending base of the lamina, forking successively as shown in Figure 6.
The veins are relatively stout, but appear to be submerged in the substance of the lamina. The midveins of the segments diverge from the rachis alternately at wide angles and continue to the tips of the segments. However, its appearance is significant as fertile fragments of Pterls^ and I have attached considerable weight to this feature in identifying the fossils.
The fossil is perhaps most like the pinnules of the extant and widespread Gleichervia {Dicrano'pteris) of South America. The ends of the segments are frayed and may have been more elongated than they are depicted. That it is the upper surface that is seen and that the pinnules are attached to the upper surface of the rachis is.
They are generally somewhat more pointed than the leaves of the small amount of recent material that is seen and is.
MONOOOTYLEDONAE INCERTAE SEDIS
The genus is interesting, its modern distribution suggesting that it was a relict genus, but to my knowledge no fossil species has so far been described. It was usually considered to belong to the same genus as the Chilean tree, but recently it has been proposed to revive the genus Disehna to accommodate it. ARTICLE 22 TERTIARY FOSSIL PLANTS FROM ARGENTINA BERRY 15 Judging from the figures, this is identical with what Duscn considered.
ART. 22 TERTIARY FOSSIL PLANTS FROM ARGENTINA BERRY 15 judge from figures, this is identical with what Duscn considered to
Leaves, small, siibcoriaceous, ovate in general outline, with an acute apex and a slightly unequal cuneate base. The genus Nothofagus includes about 17 extant austral species, restricted to southern Chile, Patagonia and Tierra del Fuego in the Western Hemisphere and to southern Australia, Tasmania and Re. The evergreen section contains 3 in South America, all 6 New Zealand species, 1 in.
They are clearly related to Fagus of the Northern Hemisphere and have long been referred to that genus. Several forms resembling Nothofagiis have been found in the Tertiary of Europe, but are equally unreliable. Recently Bandulska^^ described a Noth-ofagus from the Eocene of southern England, basing her determination on the cuticular structure which she claims distinguishes it from that of Fagus.
A large number of fossil species have been described from the Tertiary of the regions where the living species are found; at least two occur on Seymour Island, Antarctica.^^ Considering the 13 species and varieties that Dusen has described from the Tertiary of Patagonia and Tierra del Fuego, one is impressed with the thought that perhaps most of them are the slightly different leaves of a the much smaller number of botanical species. 22 TERTIARY FOSSIL PLANTS FROM ARGENTINA KOFARA 17 The present species are not uncommon in the studied collection. In the extant flora Nothofagns extends northward on the wetter Chilean side of Andesto about 33°.
Occurrence.—Southeast side of Rio Nirihuao near Casa Piedra, about 12 miles south of Lago Nahuel Huapi, Rio Negro Territory. The leaves are small in size, ovate-elliptic in outline, wider in the middle, with a narrowly rounded tip and a cuneate base. The genus has about a large number of extant species of shrubs and trees in the warmer parts of South America.
Leaf oval in general outline, with a rounded top and rounded or broadly wedge-shaped base, widest below the middle. The identity of this incomplete leaf is extremely problematic, and it may possibly represent some member of the Bignoniaceae. Hydrangea is an ancient genus, cosmopolitan extant floras and with several well-defined Tertiary species in the Northern Hemisphere, represented in Patagonia by Hydram.gei'pliylluTn afjine Dusen.^*'.
LEGUMINOSAE INCERTAE SEDIS Genus LEGUMINOSITES Bowerbank
ART. 22 TERTIARY FOSSIL PLANTS PROM ARGENTINA BERRY 19 LEGUMINOSITES species
As these leaves are variable and abundant on a single spur, I consider them to represent a single species of Sterculia^. Base varying from tapering to spiky to truncate, depending on the number and attitude of the lobes, which may be obliquely directed. Primaries three, strong, diverging from the base, or subbasal in some of the forms with a tapering base, diverging at acute angles.
In the five-lobed forms, the lateral primaries give off a short distance above their base a stout lateral which runs to the tip of the lower lateral lobe. The genus is common in the warmer parts of South America and currently extends south to Argentine Mesopotamia (about latitude 30°). Another fossil Argentine species, not unlike but perfectly distinct from Sterculia umshbwnii, has been described from the supposed Santa Cruz beds of the Chubut territory.^".
ART. 22 TERTIARY FOSSIL PLANTS FROM ARGENTINA BERRY 21
22 PROCEEDING OP THE NATIONAL MUSEUM vol.73 the existing flora, one in New Zealand and the other two in Chile in the region between 36° and 42° south latitude. If botanical systematists are right in their opinion that these belong to the same genus, then we must assume that it had a geological history, unless we are prepared to subscribe to the once fashionable but now absurd notion that a genus can tribe more than once and in different areas. Odcv/rrence.—Bluff half a league south of MataAmarilla, upper Kio Chalia, Territory of Santa Cruz.
Leaves oblong-lanceolate, wider below the middle, with an elongated gradually narrowing tip and a more acute base. Since it is impossible to determine its generic position with certainty, it is referred to the form genus Lofurophyl-Iwm. A typical species of Nectandra is present in the supposed Santa Cruz beds of the Chubut Territory,^^ so that this genus is known to have extended further south during the Tertiary than at the present time.
AET. 22 TERTIARY FOSSIL PLANTS FROM ARGENTINA BERRY 23
Somewhat similar leaves occur in several Myrtaceae and Guttiferae, but the type is especially characteristic of a significant number. Nothing of this kind was found in the presumed Miocene flora from Mirhoja, territory of Chubut. All extant genera with leaves like the fossil make their home in the warmer parts of South America, and none extend further south than northern Argentina. Secondaries about 5, medium camptodrome pairs; the basal pair is the firmest and opposite and runs close to and parallel to the lower lateral margins up to the center of the leaf, simulating lateral primaries.
This form presents characteristics that connect it with several existing genera of Bignoniaceae from the existing flora in the warmer parts of South America. 22 TERTIARY FOSSIL PLANTS FROM ARGENTINA — BERRY 25 Occurrence.—Three miles north of Estancia Chalia and li/o miles Occurrence.—Three miles north of Estancia Chalia and li/o miles south of Mata Amarilla, upper Rio Chalia, Territory of Santa Cruz .
DICOTYLEDONAE INCERTAE SEDIS PHYLLITES NIRIHUAOENSIS, new species
Balance of the venation obscure; a few thin oblique camptodrome secondary can be made, precluding comparisons with members of the family Myrtaceae, which is represented in most South American Tertiary floras, including those described from the supposed Santa Cruz beds of the Chubut Area .^* . They may represent the leaflets of some Sapindaceous genus, nor are they unlike those of the Anacardiaceous genus Schin- opsis, which is represented by good material from the Miocene of. Occurrence.—Southeast side of Rio Nirihuao, 150 meters southwest of Casa Piedra, about 12 miles south of Lago Nahuel Huapi, Territory of Rio Negro.
A specimen not unlike that recorded by Dusen from the Tertiary of Seymour Island, Antarctica, but too fragmentary.
AKT. 22 TERTIARY FOSSIL PLANTS FROM ARGENTINA BERRY 27 EXPLANATION OF PLATES
