THE FOSSIL FLORA OF THE YORKSHIRE COAL FIELD. 4'.\ 



All the spores which M. Zeiller observed were macrospores ; but, as he points out, 

 even had microspores been present in the specimens he examined, their mode of preserva- 

 tion was such that, from the minute size of microspores, it would have been impossible 

 to observe them. 



In a subsequent communication Zeiller describes and figures in detail his Sigillarian 

 cones from the coal field of Nord and Pas-de-Calais. # 



Of the various cones he describes and figures, the most interesting is Sigillariostrobus 

 Tieghemi, Zeiller, f for the pedicel of this specimen shows the true Sigillaria leaf-scar. 

 The determination of the Sigillarian affinity of this specimen carries with it all the 

 other examples he describes, as well as those formerly described by Goldenberg. 



Two figures of Sigillariostrobits Tieghemi are given, both, of which show the basal 

 portion of the cone borne on a stout leafy peduncle, which increases in width as it 

 approaches the base of the cone. On the lower part of the peduncle of fig. 1 pi. 

 xi. the acicular leaves have been removed, showing the stem to be flexuously ribbed 

 and transversely barred beneath the characteristic Sigillarian leaf-scar. Each leaf is 

 provided with a medial nerve, contained between two very close and parallel longi- 

 tudinal folds, whose origin is marked by a prominent point, corresponding to the two 

 lateral cicatricules which lie one on each side of the vascular cicatricule. This cone may 

 possibly be referable to Sigillaria polyploca, Boulay, but certainly in this identifica- 

 tion is wanting. 



At the summit of the peduncle the leaves assume the form of bracts. They are 

 inserted obliquely on the axis, single nerved, oval lanceolate, acute at the point, and 

 suddenly contracted at the base. Between the bracts, and still in position, one can see 

 the macrospores sometimes in great numbers, about 2 mm. in diameter, perfectly 

 smooth, but marked by a triradiate ridge, the arms of which are connected by a semi- 

 circular line. The macrospores are disseminated without order. " One cannot see any 

 trace of an envelope on the bracts, but on some of them can be discovered above the line 

 which separates the limb from the claw a slight arched line, which might well correspond 

 to the attachment of a membrane which originally covered the bodies in question."! 

 M. Zeiller also points out that these " bodies " much resemble the macrospores of 

 Isoetes. That these "bodies" are macrospores seems to be clear beyond all doubt. 

 Structurally they are identical with the macrospores of the cones of Lepidodendron. 



In all the cones Zeiller examined, he only found these large spores. Schimper thought 

 he saw sufficient difference in the size of the spores figured by Goldenberg to treat 

 them as macrospores and microspores,! though he was not certain of this interpretation. 

 He gives as the size of his macrospores 1*5 to 2 mm., and the microspores as 1 mm., in 



* " Cones de Fructification de Sigillaires,'MH«. d. Scienc. Nat., 6 e . ser., "Bot.," vol. xix. pp. 256-280, pis. xi.-xii., 

 1884. See also Zeiller, Flore foss. Bassin houil. d. Valenciennes, pp. 591-608, pis. lxxxix.-xc, 1886 and 1888. 

 t Ann. d. Sc, he. cit., pi. xi. figs. 1, la, 4, 4a, 4b. 

 X Loc. cit, pp. 264-265. 

 § Schimper. Traite d.paUont. veg4t., p. 105. 



