220 FLOEA OF LOWER GOAL MEASURES OF MISSOUEL 



Uuited States Geological Survey, contain a series of specimens which throw 

 much lig-ht on the unique and somewhat problematic species described by 

 Professor Lesquereux as Lepkloclendron cyclostigma} 



Pitcher's coal mine, in Hemy County, the source of most of the new 

 material, seems, as indicated both by the associated species and by the 

 matrix, to have been the source of the types of the original species, now 

 Nos. 5501 and 5502 of the Lacoe collection in the National Museum. In 

 any event it is certain, as is shown by the records and labels, that the fossils 

 described by Lesquereux came from the same vicinity. The species has 

 not been found elsewhere. 



Since the recently acquired material includes examples exhibiting many 

 new characters and features, whose interpretation is subject to differences 

 of opinion, as well as a remarkable variation in the forms of cortical impres- 

 sion, the descriptions of the important specimens will be repeated in order to 

 present all the available evidence as to the organs or appendages of the tree 

 and its systematic position. It is unfortunate that in this, as well as in most 

 other peculiarly American types of Carboniferous plants, no material is at 

 hand to show the internal organization of the tree, which is represented only 

 by somewhat flattened casts of trunks and branches, or by cortical impres- 

 sions revealing only supei'ficial details. 



The bolsters of these compressed trunks are, as was stated hj Lesque- 

 reux, variable in form as well as size. Illustrations of these varying forms, 

 which sometimes suggest the Lepidodendron dypeatum of Lesquereux,^ are 

 seen in PI. LXV and PI. LXVI, Figs. 1, 2; also PI. LXVII, Fig. 2. The 

 fragmental impression, a portion of which is seen in the first plate, is 31 

 cm. in length and 13 cm. in width, the entire breadth of the trunk being 

 miknown. It is probable, however, that some of the trunks of this species 

 grew to a considerable diameter. The figured fragment shows the impres- 

 sion or mold, over most of which the outer very thin cortex or epidermis still 

 adheres. Nevertheless, that phase in which the bolsters are represented at 

 their longest and in their more distinctly Lepidodendroid aspect is well seen, 

 the fine separative lines of the rhomboidal, acute bolsters being clear, while 

 the general features of the subtriangular or somewhat circular central convex 

 areas, which, as we shall see, represent large, compressed, roundish bosses, 



I Coal Flora, vol. ii, 1880, p. 394, pi. Ixii, hg. 5. 



- Geol. Pennsylvania, vol. ii,2, p. 875, pi. xv, tig. 5 ; pi. xvi, tig. 7. Coal Flora, vol. ii,p. 380, pi. lxiv,fig. 16. 



