55 



percent) also occurred in the shaly limestone. 



Punctatisporites (43.7 percent) continued 

 to predominate in the uppermost fossiliferous 

 shale (maceration 1175-P) sampled in the 

 cyclothem. Florinites was next in abundance 

 with 33.3 percent of the total small spore 

 assemblage. Granulatisporites (6.7 percent) 

 and Wilsonites (4.3 percent) remained at 

 about the same percentage as in the shaly 

 limestone. Triquitrites reached its maximum 

 at 5.7 percent. Calamospora (3.0 percent) 

 was not uncommon. Other genera included 

 Raistrickia, Crassispora, Illinites, Pityospo- 

 rites, and Hamiapollenites, each being repre- 

 sented by less than 1 percent of the spores 

 present. 



SPORES OF THE 



FITHIAN CYCLOTHEM, 



VERMILION COUNTY, ILLINOIS 



The type locality of the Fithian Cyclothem 

 was designated by Wilson (1944) as an out- 

 crop in NW y 2 sec. 31, T. 19 N., R. 13 W., 

 Vermilion County, Illinois, along the east 

 bank of the Salt Fork River, south of a con- 

 crete bridge, and about 2 miles south of the 

 village of Fithian. The first published use 

 of the name "Fithian Cyclothem" was made 

 by White et al. (1958). Outcrop samples 

 from the type section of the Fithian Cyclo- 

 them were collected for this investigation; 

 they are described at the end of the report. 

 The Fithian Cyclothem is stratigraphically 

 equivalent, or approximately so, to the Flat 

 Creek Cyclothem of southwestern Illinois 

 (Kosanke, personal communication, 1961). 



Of the seven samples from the Fithian 

 Cyclothem (text fig. 15) only the marine 

 limestone (maceration 1170-F) failed to yield 

 spores. Those obtained from the remaining 

 samples are generally in a good state of pres- 

 ervation, especially those from the underclay, 

 which had the best preserved spores of any 

 underclay macerated for this study. The 

 greatest diversity of species and genera was 

 found in the shale (maceration 1170-G) 

 overlying the limestone, whereas the least 

 variety was found in the shale (macerations 

 1170-D, E) between the coal and limestone. 



At the top of the underclay (maceration 

 1170-A) Calamospora was the dominant 

 genus and was at its maximum abundance 



for the cyclothem, making up 55.3 percent 

 of the small spore assemblage. Florinites 

 (14.7 percent) was second and Punctatispo- 

 rites (15.0 percent) third in abundance. Tri- 

 quitrites (4 percent), Cadiospora (2.7 per- 

 cent), Granulati pontes (2.3 percent), En- 

 dosporites (1.3 percent), and Laevigatospo- 

 rites (1 percent) also occurred in the under- 

 clay. The "bisaccate grain 2" accounted for 

 2 percent of the total, and the remainder was 

 made up of Raistrickia, Crassispora, and un- 

 assigned spores, each of which were less than 

 1 percent of the spore population. 



Punctatisporites (40.2 percent) was the 

 most abundant genus in the bottom half of 

 the coal (maceration 1170-B). Laevigato- 

 sporites increased significantly to reach its 

 maximum (29 percent) in this sample. Cala- 

 mospora ( 10.4 percent) , the third most domi- 

 nant genus, and Florinites (1.8 percent) de- 

 creased markedly from their profusion in the 

 underclay. Vesicaspora (6.6 percent), Tri- 

 quitrites (5 percent), and Raistrickia (1.4 

 percent) reached their greatest occurrence in 

 the lower half of the coal but were not nu- 

 merically significant in terms of the total 

 spore assemblage. Granulatisporites (4.6 per- 

 cent) was rather common. Cirratriradites, 

 Reticulatis pontes, and Endosporites totaled 

 less than 1 percent. 



The small spore assemblage in the upper 

 half of the coal (maceration 1170-C) was 

 dominated by Punctatisporites (64.4 percent) 

 which there reached maximum distribution. 

 Calamospora (13.4 percent) showed a slight 

 increase over the percentage found in the 

 lower part of the coal while Laevigatosporites 

 (12.4 percent) decreased sharply. Crassispora 

 (3.4 percent) was statistically well repre- 

 sented. Other genera included Florinites (1.8 

 percent), Endosporites (1.4 percent), Rais- 

 trickia (1.2 percent), Vesicaspora (1.0 per- 

 cent), Reinschospora, Reticulars pontes, Tri- 

 quitrites, Alatisporites, Conuolutispora, Gran- 

 ulatisporites, and Indospora. The last 6 gen- 

 era were represented by less than 1 percent 

 each. 



The most striking change in the distribu- 

 tion of small spore genera in the dark gray 

 shale (maceration 1170-D) overlying the coal 

 was the great increase in Crassispora, from 

 3.4 percent in the upper half of the coal to 

 78.7 percent in the shale. Endosporites (12.3 



