592 
Notes. 
those of the former species, and similarly inserted, but the spores 
are quite different. They are smaller than those of S. insignis , and 
have the form of quadrants of a sphere, with narrow wings along 
their three angles. 
The genus is separated from Lepidostrobus, mainly on account of 
the very different mode of insertion of the sporangia, a character 
which is accompanied by differences in the form of the sporophylls 
and sporangia, the structure of the sporangial wall and of the spores, 
and the whole habit of the strobilus. 
Spencerites , and especially S. insignis , bears a considerable re- 
semblance to the Sigillariostrobus Crepini of Zeiller, but cannot be 
united with the genus Sigillariostrobus , for the insertion of the 
sporangia in the latter, as shown in the Sigillariostrobus ciliatus of 
Kidston, is totally different. The author is much indebted both to 
M. Zeiller and Mr. Kidston, for the loan of their specimens for 
examination. 
The generic and specific characters may provisionally run as 
follows 
Spencerites , gen. nov. 
Cone consisting of a cylindrical axis, bearing numerous simple 
sporophylls, arranged spirally, or in crowded alternating verticils. 
Sporophylls short, formed of a sub-cylindrical pedicel, expanding 
into a large peltate lamina. 
Sporangia solitary on each sporophyll, inserted, by a narrow base, 
on the upper surface of the lamina, but free from the pedicel. 
Sporangial wall consisting of a single layer of prosenchymatous 
cells. Spores winged. 
i. Spencerites insignis (Will.). 
Lepidostrobus insignis , Will. Organization of the Fossil Plants of 
the Coal-measures, Part X, Phil. Trans. 1880, p. 502. 
Lepidodendron Spenceri , Will. Loc. cit. Part XVI, Phil. Trans., 
1889, p. 199. 
Cone pedunculate; peduncle bractigerous. Whole cone 8-10 mm. 
in diameter. Axis 3-5-5 mm. in diameter. Sporophylls 2-2 5 mm. 
long ; lamina distinctly peltate, vertically elongated. 
Sporangia approximately spherical. Spores tetrahedral, becoming 
spheroidal when free, with a hollow equatorial wing. Maximum 
