84 



ILLINOIS STATE GEOLOGICAL SURVEY 



the Tarter Cyclothem. Unfortunately, only 

 the coarse residue of the uppermost inch 

 (maceration 604A) of the Tarter Coal at 

 this locality is now available; that of the 

 lower 12 inches below a 12-inch parting is 

 missing. 



The following genera and species were 

 identified from the Willis Coal (maceration 

 625A-B). Relative abundance notations of 

 coals sampled in two or more segments 

 are listed subsequently in the following 

 order: (top, lower) or (top, middle, lower) . 



Triletes triangulatus 



(A,A) 



Renisporites confossus n. sp. 



(A,A) 



T. brasserti 



(C,A) 



T. ramosus 



(A,C) 



T. mamillarius 



(A,C) 



Cystosporites varius 



(A,C) 



Spencerisporites cf. S. radiatus (A,P) 



Punctatisporites cf. P. obesus (P>C) 



Calamospora cf. C. sinuosa (C,P) 



T. auritus (C,R) 



T. globosus var. (C) (C, -) 



Monoletes (R>R) 



Cystosporites breretonensis ( -, P) 



T. superbus (R, - ) 



One other sample of the Willis (?) Coal 

 (maceration 631) did not contain the great 

 diversity of spore types. T. ramosus is dom- 

 inant; T. mamillarius, T. globosus var. (C), 

 Calamospora cf. C. sinuosa, S. cf. S. radia- 

 tus, and T. triangulatus also are repre- 

 sented. 



For comparison, the following genera 

 and species were identified from the Tarter 

 Coal (maceration 901), NE14 sec. 26, T. 9 

 N., R. 1 W., Warren County, Illinois: 



Triletes brasserti (A) 



Renisporites confossus n. sp. (A) 



T. triangulatus (P) 



Punctatisporites cf. P. obesus (P) 



Monoletes (P) 



Calamospora cf. C. laevigata (P) 



T. ramosus (R) 



Cystosporites varius (R) 



Spencerisporites cf. S. radiatus (R) 



Triletes brasserti is the dominant species, 

 accounting for 90 percent of the mega- 

 spores. T. brasserti also was dominant in 

 the uppermost inch of the Tarter Coal 

 (maceration 604 A) at another locality. Spe- 

 cies from maceration 604 A not represented 

 in maceration 901 are T. auritus, T. ap- 



pendiculatus?, T. cf. T. eregliensis, and 

 possibly Calamospora cf. C. sinuosa. 



However, one sample (maceration 914) 

 of the Tarter Coal, 6 inches thick, from 

 Mercer County, has a unique assemblage. 

 Triletes auritus makes up 95 percent of the 

 large spore assemblage; other genera and 

 species represented are T. cf. T. hirsutus, 

 T. horridus, Spencerisporites cf. S. radiatus, 

 Cystosporites, and Monoletes. The assem- 

 blage is unlike those of the other samples 

 of Tarter or Willis Coals, but in the dom- 

 inance of T. auritus and the occurrence of 

 T. cf. T. hirsutus is similar to the assem- 

 blage of the overlying Pope Creek Coal 

 from the same locality. 



The Willis Coal contains abundant and 

 greatly diverse types of spores. The Tarter 

 Coal, with the exception of the one sample 

 from Mercer County, has a similar but less 

 diversified assemblage, lacking some of the 

 species typical of the Willis Coal, such as 

 Triletes mamillarius and T. globosus var. 

 (C). The two coals are characterized by an 

 abundance of zonate megaspores. Those of 

 T. brasserti even occur in tetrad arrange- 

 ment in both coals. This species also is 

 known from one sample of the Pope Creek 

 Coal. Triangulate spores are abundant as 

 in the Babylon Coal. Kosanke (1950) re- 

 ported Cirratriradites as the subdominant 

 genus of the Willis and Tarter Coals and 

 that it was present in fair abundance in the 

 Babylon Coal. This occurrence of Cirratri- 

 radites parallels the high incidence of tri- 

 angulate megaspores. 



Both Renisporites confossus and Puncta- 

 tisporites cf. P. obesus appear to be re- 

 stricted to the Willis and Tarter Coals. Tri- 

 letes globosus var. (C) is known only from 

 the two samples of Willis Coal. Spenceri- 

 sporites cf. S. radiatus is present or abun- 

 dant for the first time since its abundant 

 representation in the Reynoldsburg Coal of 

 the Caseyville Group. Monoletes or other 

 evidence of medullosans, such as resin rod- 

 lets, are not common. The assemblages of 

 the Tarter and Willis Coals are among the 

 most distinctive of any of the Pennsylva- 

 nian coals and are readily distinguishable 

 from those of older and younger coals. 



