54 



POSSIL PLANTS. 



Fig. 4^ (magnified 5 diameters) shows two Scales and two Sporangia, each contain- 

 ing Macrospores, all nearly of the same size ; fourteen are seen in the upper Sporangium, 

 and fifteen in the lower one. The apex of the Scale is stronger, and diverges more from 

 the vertical direction than most of the specimens previously described. 



This Lepidostrohus may be of the same species as No. 21 and No. 22, but for the 

 present it is probably better to distinguish it as a provisional species by the name of 

 tenuis. 



§ 5. SpECiJiiiN No. 25 ; Lepidostrobus levidensu. PI. X, figs. 1, \a, \h. 



Specimen No. 25 (PI. X, fig. 1, natural size) represents a beautiful Cone in a com- 

 pressed state, and nearly perfect, six and a half inches in length and eight tenths of an 

 inch in breadth ; its central column or axis measuring one tenth of an inch across. This 

 is longer, and tapers more than any of the specimens previously described. Excepting a 

 small portion, it shows the apex. The base of the Cone is broken off", so we cannot now 

 see how far it may have extended ; but for the space of an inch the lowest part of the 

 Cone shows Scales or Bracts arranged in spiral order around the column, springing out 

 at right angles to it, and supporting elongate oval Sporangia, full of Macrospores, one 

 twentieth of an inch in diameter. The upper portion of the Cone is for the most part 

 covered with rhomboidal scales ; but on the right hand side, near the top, are exposed 

 some oval Sporangia, containing very small spheroidal bodies, converted into a substance 

 like paraffine, and resembling Microspores. Thus we have, in this case, a Cone, with the 

 form and external characters of a Lejndostrobus, possessing two kinds of Sporangia, namely 

 the lower series inclosing Macrospores similar to those described in the previous specimens, 

 and the higher set containing Microspores resembling those in Lepidostrobus Dabadianus, 

 Schimper. 



Fig. \a (magnified 2^ diameters) represents a portion of the Column of the Cone, 

 showing the Scars of the Bracts, arranged in quincuncial order, and four Bracts on each 

 side of the Column, at right angles to it, and supporting long-oval Sporangia, containing 

 from fourteen to sixteen Macrospores in each. The Macrospores are chiefly composed of 

 granular bisulphide of iron on a coriaceous covering of a yellowish colour. Their insides 

 consist also of grains, resembling bisulphide of iron. The Column, Bracts, and Sporangia 

 are converted into coal, and as yet have afforded no evidence of their former structure. 



Fig. \b (magnified 5 diameters) represents a Bract, supporting an irregularly oval 

 Sporangium, full of small spheroidal bodies, converted into a yellowish substance like 

 paraffine, and resembling Microspores. Of course these Microspores are not so clear and 

 distinct as those seen in Specimen No. 17, by the aid of transmittent light; but they are 

 of the same substance, and much like those bodies when seen by reflected light. They 

 appear to be about the same size as those found in Lepidodendron Harcourtii. 



