— 845 — 
On account of the associotion of the specimens in the bed filled 
with the leaves of Gangamopteris, to the northeast of Minas, Iam 
disposed to believe Derbyella may ultimately prove to be the fertile 
scale leaf of the latter genus. The nervation in the interior of the 
specimens is too obscure for distinct perception, but I am inclined 
to believe that it anastomoses in a relatively large, elongated, an- 
gular mesh. Should the nervation prove to possess these characters 
its identity with Gangamopteris will appear the more probable. 
1 take pleasure in naming this genus in honor of the distin- 
guished geologist of Sao Paulo who has done so much to build. up 
our knowledge of the palaeontology as well as of the geology of the 
Republic of Brazil. The typeof the genus is Derbyella aurita. 
Derbylla aurita n. sp. 
Pl. IX, Figs. 4, da, 2, 2a, 3. 
Small, oblong, or oval-oblong, asymetrical foliar organs, 1.25—2cm. 
in length, S—10mm, in width, round at the apex, contracted abruptly 
at the base ; lamina rather thick, nearly smooth over the central area, 
and cut at the border in very small, narrow, oval or oblong obtusely 
rounded, radiate lobes, 2.5—3.5mm, in length, 1—1.5mm. in width, 
onthe base of each of which is deeply seated a large round sporan- 
gium (?) in diameter nearly equalling the width of the lobe ; lobes 
slightly enlarged about the base, usually slightly twisted and ventrally 
shallowly concave beyond the sporangium (2) and more or less turned 
upward, the convex (dorsal) surface being directed backward nerva- 
tion not well seen, rather distant. flabellate from the base, dicho- 
tomous, a single nerve passing upward to near the base of each 
lobe, tohere it forks acutely, the short distal (ventral), division 
arching slightly upward in passing to the sporangium (2) the lower 
division completely traversing the lobe; impression of the sporangia (2) 
rather deep, round, or neariy so, about Imm. in diameter, andl 
slightly conver at the center with avery small, obscure, mamimillate 
sear 
The plant described above is represented by Jut two specimens 
which, with one counterpart, are illustrated on PI. IX, Figs. 4, 2, and 3. 
The form of the leaf is shown in Fig. 2. The impression of the spo- 
rangium (?}), which is situated at the base of each lobe, is shown in 
n5G0 58 
