130 Structure of Lepidodendron and Sigillaria. 



was derived from the roof of the "Diamond," or G, seam. These 

 are casts ; but I shall always speak of the reverse, or cortex. 

 The scars and leaf-bases of Figs. 1 to 5, were elevated, with 

 sharp relief ; consequently, the forms are not due to flattening. 



The fruit-scars, which are irregularly dispersed among the 

 leaf-scars of Fig. 1, are slightly elevated, angular by compres- 

 sion, and without distinct markings. But a very similar 

 specimen in Prof. J. S. Newberry's collection has the fruit- 

 scars less angular, or even sub-rotund, and with elevated cir- 

 cular central area. They are similar to the fruit-scars of Prof. 

 Dawson's S. Zorwayana, Geol. Sur. of Canada, Pep. on the 

 Fossil Plants of the L. Carb. etc., 1873. And his remarks 

 concerning the probability of those scars being the places of 

 attachment of fruits like Trigonocarpa, single or in racemes, 

 or like Antholites, and the impossibility of the fruits being the 

 strobiles of Schimper, apply with equal force to these. 



The production of the fruit apparently caused, or was ac- 

 companied by, a retardation of the upward, or vegetative 

 growth of the branch, and a consequent crowding of the leaf- 

 bases below the ring of fruiting. 



The most natural of the forms upon Fig. 1 is that having 

 the scars farthest apart, as thns affording free development and 

 giving greater resemblance with the trunk. The upper half of 

 Fig. 1 is certainly S. l&pidodendrifolia. This I have deter- 

 mined fully by comparison with other undoubted specimens. 

 The surface is not striated, but finely dotted or granulated, a 

 not uncommon appearance. The cortex had not sufficiently 

 expanded to produce the longitudinal furrowing seen on older 

 specimens. However, the cracking of the bark had begun to 

 obliterate the leaf-bases on the lower half of the same frag- 

 ment. In this connection, I would observe that I found a 

 specimen of typical S. lejpidodendrifolia near these fossils. The 

 rock of Fig. 6 is too coarse to preserve the striation of the 

 bark. 



It is quite as certain that the lower half of Fig. 1 is S. 

 JBrardii, Brongt ; and that Figs. 3, 4 ? are S. JHenardi, Brongt. 



