49 



Schopf, Wilson, and Bentall (1944), Cyclo- 

 granis pontes was included with Punctati- 

 s pontes in all the figures (text figs. 13-16) 

 showing distribution of genera. 



In the underclay (maceration 1128-F), the 

 lowest stratum sampled in the cyclothem, 73 

 percent of the spores were Punctatis pontes. 

 Calamospora was second in relative abund- 

 ance (10 percent) and Endosporites was third 

 (5.3 percent) . Gravisporites proved to be 

 more abundant (3.3 percent) in the under- 

 clay than in the other strata sampled. Flori- 

 nites (3.0 percent), Laevigatosporites (1.3 

 percent), Triquitrites (1.7 percent), and 

 Granulatis pontes (2.0 percent) also were 

 found in the underclay. 



The relative abundance of small spore 

 genera in the No. 8 Coal (maceration 1128- 

 G) did not differ greatly from that in the 

 underclay. Punctatis pontes (83.4 percent) 

 was at its peak in the coal, but Calamospora 

 (7.4 percent) and Endosporites (3.4 percent) 

 decreased in abundance. Laevigatosporites, 

 Granulatis pontes, Triquitrites, and Florinites 

 were relatively rare. Cadiospora, Reinscho- 

 spora, Trivolites, and Raistrickia occurred in 

 the coal but were not observed in the statis- 

 tical count. 



Three samples from the gray, carbonaceous 

 shale overlying the coal were examined. In 

 the lowest sample (maceration 1128-H), 

 Punctatis pontes accounted for well over half 

 (60.3 percent) the spore population. The 

 most conspicuous change in the spore distri- 

 bution was the increase in Calamospora (19.7 

 percent), Endosporites (10.7 percent), and 

 Florinites (5.7 percent). Laevigatosporites, 

 Triquitrites, Raistrickia, Granulatis pontes, 

 and Lycospora each formed less than 2 per- 

 cent of the total spore population. 



In the sample (maceration 1128-1) from 

 the middle of the shale sequence, Calamo- 

 spora (36.3 percent) was more abundant 

 than in any other sample from the cyclothem 

 and was almost as plentiful as Punctatispo- 

 rites (38.3 percent). Granulatis pontes (6 

 percent) also reached its maximum for the 

 cyclothem. Florinites (7.3 percent) was only 

 slightly more common than in the lower 

 shale sample. Endosporites (4 percent), 

 Laevigatosporites (3.7 percent), and Lyco- 

 spora (3.3 percent) were in significant abun- 

 dance, but Triquitrites, Indospora, and Den- 

 sosporites each accounted for less than 1 per- 



cent. Although rare, the presence of Denso- 

 sporites is significant and will be discussed 

 later. 



In the sample (maceration 1128-J) taken 

 from the upper part of the gray shale, the 

 top of the cyclothem, Florinites (22 percent) 

 was at peak abundance for the cyclothem, but 

 Punctatis pontes (47 percent) was still the 

 dominant genus. Calamospora (15.3 per- 

 cent), Granulatis pontes (3.7 percent), and 

 Endosporites (0.3 percent) were notice- 

 ably less important than in the under- 

 lying sample, while Lycospora (3 percent), 

 Laevigatosporites (3 percent), Triquitrites 

 (<1 percent), and Densosporites (<1 per- 

 cent) appeared in about the same percentage 

 as in maceration 1128-1. Wilsonites, Cirra- 

 triradites, Reticulatis pontes, Ahrensis pontes, 

 Secarisporites, Crassispora, and Pityosporites 

 appeared for the first time. Three species (4 

 specimens) of hystrichospheres also were ob- 

 served. 



In the dark gray, shaly, marine limestone 

 (maceration 1128-K) directly overlying the 

 cyclothem, Punctatis pontes accounted for up 

 to 67.3 percent of the spore assemblage. 

 Calamospora (19.7 percent) and Endospo- 

 rites (3.7 percent) were second and third in 

 relative abundance. The most conspicuous 

 change from the underlying shale sample is 

 the diminution of Florinites. The percentages 

 of Laevigatosporites, Granulatis pontes, and 

 Triquitrites were not significantly different 

 from those of maceration 1128-J. Lycospora, 

 Reinschospora, and Indospora were also pres- 

 ent but rare. 



In the sample from the gray shale (macera- 

 tion 1128-L) above the limestone, Calamo- 

 spora (10 percent) was again subordinate 

 to Punctatis pontes (70.7 percent.). Laevi- 

 gatosporites (8 percent) was at its maximum 

 for the cyclothem, whereas Granulatis pontes 

 (5.3 percent) and Florinites (4.3 percent) 

 increased slightly in relative abundance. Wil- 

 sonites, Crassispora, Gravisporites, Reinscho- 

 spora, Indospora, Triquitrites, and Vesica- 

 spora each made up less than 1 percent of 

 the total spore population. 



Franklin County, Illinois 



Samples from the diamond drill core of 

 the Trivoli Cyclothem from Franklin County, 

 Illinois, were macerated for comparison of 



