LEPIDOSTROBUS. 



51 



vessels of different sizes, more regular and of less diameter towards the outside. There 

 is also an outer zone of tissue, with interruptions in it. 



This is a representation of the specimen described and figured (p. 110, Plate VI, figs. 

 2 and 3) in my paper On some Fossil Plants, showing Structure, from the Lower Coal- 

 Measures of Lancashire." ^ It is here reproduced for the purpose of showing the structural 

 similarity of the axis of the Cone now under consideration with that of Lepidodendron 

 vasculare, and its difference from Lepidodendron Harcourtii (see above, page 48). 



§ 2. — Specimens Nos. 21 and 22 ; Lepidostrobus Russellianus, sp. nov. PI. IX, figs. 1, 



1 «, 2, 2 



Specimen No. 21, Lepidostrobus Russellianus (Plate IX, fig. 1), natural size, is a com- 

 pressed imperfect Cone, six inches in length, by eight tenths of an inch in breadth, 

 having a central colimm one tenth of an inch in diameter. The upper portion of the 

 fossil is not preserved, so its form is unknown ; but the lower portion, for about two 

 inches, shows the scales or bracts of the Cone, springing nearly at right angles to the 

 colunm, and arranged in spiral order, together with numerous disc-shaped bodies, about 

 one thirty-second of an inch in diameter, having their insides smooth and coriaceous, and 

 their outsides granular, but showing no clear evidence of a triradiate ridge, although there 

 is some sign of an elevation on some of the discs.^ The bracts on the upper part of 

 the Cone do not show such bodies. 



The matrix in which the fossil is imbedded is a Black Band Ironstone ; but the disc- 

 shaped bodies are chiefly composed of granular bisulphide of iron, coating the coriaceous 

 layer, of a yellowish colour, on their outsides ; whilst their insides are full of a granular 

 substance of a bright-yellow colour, also resembling bisulphide of iron. The column, 

 scales, and Sporangia are all converted into coal, and as yet have afforded no evidence of 

 their former structure. 



This and the four next described specimens are from the Coal-measures, near Airdrie, 

 Scotland, and were found by Mr. James Russell, of Chapelhall. 



Pig. 1 a (magnified five diameters) represents a portion of the column of the Cone 

 and two Sporangia, each containing fifteen of the disc-shaped bodies, in seven pairs and 

 one at the end. The scale or bract goes out nearly at right angles from the column to 

 the end of the Sporangium, when it turns upwards nearly parallel to the stem. Both the 

 scale and Sporangium have been converted into a mass of coal. The discs are both 

 concave and convex ; and some of them appear as if they had been separated into two 

 by the splitting of the specimen. 



' ' Quart. Journ. Geol. Soc' for May, 1S62, vol. xviii. 



2 In this, as well as in the other specimens of macrospores hereinafter described, no conclusive evidence 

 of a triradiate ridge has been observed. 



