See 
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NOTICE OF A FOSSIL LYCOPODIACEOUS FRUIT. 7 
trace of a line of regular debiscence, are points in which they resemble 
specially the sporangia of Jsoé¢es ; but in this genus the sporangia are 
situated at the very base of the leaves, which are borne on a very short 
and bulbiform stem. 
In the fossils, on the contrary, the sporangia are borne on a kind of 
bracts, or squameeform leaves united in a spike, which, like those of 
Selaginella, probably terminated the branches. 
There is, then, here a singular combination of characters : sporangia 
analogous to those of Zsoé/es, arranged in a spike similar to that of Lyco- 
podium, but much larger. 
The great size of their-organs is, indeed, one of the striking charac- 
teristics of these spikes. It agrees with the arborescent habit of Lepido- 
dendron, compared with that of the living Lycopodiacee, but it is not on 
this account the less remarkable, as the organs of reproduction do not 
generally follow the growth of the vegetative organs; the largest tree- 
ferns have not greater sporangia than the smallest species ; and, in the 
same way, the flowers of our large trees are often smaller than those of 
the most humble herbaceous plants. 
In these paleeozoic plants the growth has been simultaneous in the 
two systems of organs. 
Thus, Zepidodendron, a genus of arborescent Lycopodiacee, had 
spikes of fructification agreeing in their size with the cones of Firs 
and Cedars, containing very large sporangia, rather than with those of 
Isoétes, which they resemble in form and structure. 
And the question remains to be considered, have the fruits of true 
Lepidodendron, i.e. Lepidostrobus, which have been described by Dr. 
J. D. Hooker, only one kind of spores, or has the imperfect state of the 
specimens prevented the true nature of the spores contained in the 
lower sporangia of the spike from being ascertained? The form of the 
spores of Lepidostrobus differs so much from those of the microspores 
of Triplosporites as to induce me to consider these plants as belonging 
to different genera, and that the genus Triplosporites of Robert Brown 
ought to be retained. 
The three known specimens of this fossil do not enable us to esta- 
blish its true geological position. The origin of that described by R. . 
Brown and of the one in the Strasbourg Museum is entirely unknown. 
That which I have just described was found in the drift in a Pyrenean 
valley far from the formation in which it was originally preserved ; 
