CZEKANOWSKIA. 277 



a Ginkgo-hke tree in which the short shoots were deciduous. The 

 form of the needles suggests a comparison with Pimti, Larix, or 

 ddrus, but the distinct forking in several of the Siberian examples 

 described by Heer led that author to cite the maidenhair-tree 

 {Ginkgo) as the more probable type with which to compare the 

 fossils. In some of the more perfect specimens the tuft of long 

 needles is enclosed at the base by a few small scale-leaves, as in 

 the short shoots of Pinus and Larix. Several of Heer's specimens 

 exhibit numerous oval swellings on the leaves, which it is suggested 

 may possibly represent spores ; but if the plant is a Conifer, and 

 not a Vascular Cryptogam, it is possible, he suggests, that these 

 swellings aro tho result of the ravages of a fungus. 



The frequent association of small seeds with the leaves of 

 Czekanowskia led Heer to regard the two as parts of the same plant. 

 The two Siberian species instituted by Heer, Czekanowskia rigida 

 and C. setacea, closely resemble one another, and it is, I believe, 

 impossible to separate the two forms by any satisfactory differences. 



In 1873 Saporta 1 included Solenites under Unger's genus 

 Jxiiipaulia; but in a later work 2 both Jeanpaulia and Solenites are 

 transferred to Saporta' s genus Trichopitys, founded on a Permian 

 plant, T. Iirftromorpha. Saporta refers more particularly to the 

 type named by Lindley & Hutton Solenites furcata. By most 

 authors, such specimens as those originally named by Lindley & 

 Hutton Solenites Murray ana are placed in the genus Czekanowskia, 

 and referred to the Coniferse. Schimper, 3 on the other hand, 

 includes Solenites Murray ana in the genus Isoetes. The form of 

 the leaves and their occurrence in tufts lend support to the 

 comparison with this genus, but the occurrence of the scale-leaves 

 forms a point of resemblance to coniferous shoots. Solms-Laubach 

 includes Solenites Murrayana 4 as a possible member of the Isoeteae, 

 but expresses considerable doubt as to its true position ; he points 

 out the desirability of examining the structure of the epidermis to 

 ascertain if stomata are present, a character, he adds, which would 

 strengthen the comparison with Czekanowskia. The thin carbo- 

 naceous film representing the needle-like leaves of Solenites 



1 Saporta (73), p. 461. 



- Ibid. (84), p. 263. 



:i Schimper (70), p. 75. 



4 Solms-Laubach (91), p. 192. 



