— 579 — 
The reference of Zeiller’s species to the genus Dadozylon is, in 
my judgment, very seriously to be questioned. The prominently tri- 
carinate form of the large pith, the generative function of the keels, 
the irregularity in form of the tracheides, the usually uniseriate and 
sometimes distant arrangement of the areoles and especially the exactly 
round figure of the small pores seem to me to exclude the species from 
Endlicher’s Dudoxylon while arguing for recognition as a distinct 
generic type. 
The presence of a carinate pith in Dadoxylon Pedrot reminds one 
of Scott’s Dadoxylon Spenceri (1) from the Halifax coalfield, though 
in the British specimen the pith is 5-keeled, while at the same time it 
contains mesarch primary (centripetal) wood strands. 
Concerning the decomposition of these woods it is very interesting 
to observe that Zeiller finds thecells of the medullary rays infested 
with small hacterioid corpuscles, 7p. 8y in diameter, which he re- 
gards as most closely allied to the Micrococus hymenophagus var. 
a of Renault (2). 
Locality : Valley of the Jaguaraéo, Rio Grande do Sul. The type is 
in the collection of the Ecole supérieure des Mines, Paris. 
Dadoxylon nummulartum n. sp. 
Pl, xiii, Figs. 1-4 
Tracheides in fairly regular radial rows, extremely long, narrow, 
sinuate, acute, relatively large though varying greatly in diameter 
in the same section, generally squarrose, though often somewhat 
rounded at the angles, with a tangential diameter averaging 34», 
usually greater than the radial diameter, especially in the larger 
cells ; medullary rays very numerous, close, usually not, more than one 
or two tracheides distant, 1-30 cells, averaging 6 or 7 in height, mostly 
uniseriate, though frequently biseriate for the height of two or three 
cells ; ray cells distinctly squarrose where uniseriate, somewhat trre- 
gular in form where biseriate, generally higher than broad, averaging 
30pin height, usually rectangular in radial section, and ordinarily 
(1) Trans. R, Soc. Edinb, vol. XL. pt. 2, 1902, p. 357 pl. Il, fig. 42, 13; pl. VI, 
figs. 24, 20. 
(2) Bu'l, Soc. hist. nat. Autun, vol. vii, 1895, p. 458, Fl, foss. bassin houill. et 
perm. d’Autun et Bpinac, pt. 2, 1890 p. 465. fig. 105. 
