60 



The distribution of Crassispora is peculiar. 

 It is abundant (78.7 percent) in the shale 

 directly overlying the coal of the Fithian 

 Cyclothem but composes only 3.4 percent of 

 the spore assemblage in the upper half of 

 the coal and is absent in the lower half of 

 the coal. It is the most abundant genus (62 

 percent") in maceration 1 1 22- J, a limestone, 

 but accounts for only 0.3 percent of the small 

 spore population in a shale (maceration 

 1122-G^ 22 feet below. Crassispora occurs 

 throughout most of the Trivoli Cyclothem in 

 Franklin County but does not become a ma- 

 jor constituent. 



Gravis -pontes is a major component of the 

 spore population at the top of the underclay 

 of the middle and upper coals described from 

 the section of the Henshaw Formation stud- 

 ied. It is also abundant in the shale (mac- 

 eration 1170-E) above the coal of the Fithian 

 Cyclothem. 



Cadiospora, probably closely related geneti- 

 cally to Gravis porites, was found only in coal 

 (maceration 1122-P) or directly above and 

 below coal (Fithian Cyclothem) . 



The vertical ranges of Densosporites and 

 Lycospora in coal have proved valuable for 

 correlation in many regions. In the coals of 

 the Illinois Basin, the range of Lycospora 

 extends as high as the Athensville Coal Mem- 

 ber below the No. 8 Coal (Kosanke, 1950, 

 pi. 17) , whereas Densosporites reaches only 

 into the DeKoven Coal Member at the top 

 of the Spoon Formation. Cross and Schemel 

 (1951, p. 128) placed the upper limit of the 

 Lycospora Zone "approximately at the Des 

 Moinesian-Missourian (lower mid-McLeans- 

 boro) boundary in the mid-continent area 

 and in the middle Conemaugh in West Vir- 

 ginia." The upper limit of Densosporites is 

 slightly above the Pottsville-Allegheny bound- 

 ary in West Virginia. Densosporites was re- 

 corded from the Jura Basin, France, by Al- 

 pcrn (1959, p. 297-308) from coal of the 

 Stephanian B, which is stratigraphically 

 equivalent to approximately the middle of 

 the McLeansboro Group of Illinois. 



In the present investigation, Densosporites 

 and Lycospora were found in shales from 

 the Trivoli Cyclothem above and below the 

 No. 8 Coal, and from the Flenshaw Forma- 

 tion. The spores in the Henshaw shales are 

 well above the vertical ranges of the genera 

 previously determined from coal studies in 



North America. Collins (1959, p. 44) found 

 Densosporites in the Ames Shale, also above 

 the range of the genus as determined by spore 

 studies of coal. The occurrences of Denso- 

 sporites and Lycospora in clastic beds above 

 their known vertical ranges in coal in North 

 America can be attributed to deposition of 

 reworked older sediments. The fact that these 

 genera were usually found together in the 

 clastic sediments tends to support this expla- 

 nation. Some of the species of Densosporites 

 and Lycospora found during this investiga- 

 tion were identified with species described 

 from coals older than the McLeansboro. 

 Species of the two genera that could not be 

 identified may have been undescribed species 

 deposited from reworked older sediments. 



A second possible explanation for the pres- 

 ence of Densosporites in the upper Pennsyl- 

 vanian is that the spores may have been borne 

 by lycopods that lived in environments at 

 some distance from the coal swamps. Species 

 of Densosporites have been correlated with 

 minute, probably herbaceous, lycopod cones 

 (Chaloner, 1958b, 1962; Bhardwaj, 1958), 

 and some of these lycopods may have lived 

 in slightly higher regions and survived after 

 the lycopods that lived in the coal swamps 

 became extinct. Spores borne by herbaceous 

 lycopods, rather than being widely distrib- 

 uted, would be quickly buried by clastic sedi- 

 ments, and so few spores might reach the 

 coal swamps that there would be little likeli- 

 hood of finding them in coal macerations. 

 The fact that Alpern reported Densosporites 

 in a Stephanian coal of France indicates that 

 some species of De?isosporites-producmg lyco- 

 pods may have continued to live in late Penn- 

 sylvanian time. 



The large number of Lycospora found in 

 shale between the Athensville Coal (the 

 youngest coal in which Lycospora has been 

 reported) and the No. 8 Coal in the Trivoli 

 Cyclothem in Franklin County are probably 

 within the normal vertical range of the genus 

 in the Illinois Basin. 



Florinites is a common constituent in all 

 the cyclothems studied except the upper part 

 of the Henshaw Formation. Florinites is most 

 plentiful in the shales above the coals in the 

 Trivoli Cyclothem. After marine inundation 

 of most of the coal swamp, these spores, 

 which were equipped with bladders for wide 

 dispersal by wind, were probably carried out 



