34 



ILLINOIS STATE GEOLOGICAL SURVEY 



These spores are very similar to, and 

 probably identical with, those originally 

 described by Arnold (1950) . However, 

 none is as large or as small as he described, 

 nor were they ever found in such abun- 

 dance as in the Williamston Coal, a spore 

 coal. 



Dijkstra (1952b, p. 167) pointed out that 

 the morphology of the spores of Triletes 

 dentatus Zerndt is apparently identical to 

 that of T. ramosus Arnold, but said that 

 the ". . . only difference between these two 

 species is difference in age." T. dentatus, 

 according to Dijkstra, is known from the 

 Westphalian C (highest part) and D from 

 Poland, Turkey, France, and the Nether- 

 lands. In addition to those of the Williams- 

 ton Coal, Arnold found a few spores of T. 

 ramosus in the shale below Cycle "A" at 

 Grand Ledge and from the Big Chief No. 8 

 mine at St. Charles, Michigan. 



The same comments that Dijkstra made 

 in his distinction between spores of Triletes 

 rotatus and T. dentatus apply equally well 

 in the distinction between those of T. ro- 

 tatus and T. ramosus. Compared to spores 

 of T. rotatus, the T. ramosus spores are 

 generally larger, possess distal appendages, 

 and more numerous equatorial appendages. 

 Although it is possible that T. ramosus may 

 prove to be a later synonym of T. dentatus, 

 the Illinois spores are referred to T. ra- 

 mosus because comparative material was 

 available. The first really definitive descrip- 

 tion and adequate illustration of Zerndt's 

 species was published by Dijkstra (1952b, 

 p. 166, 167) . The only spore illustration 

 that Zerndt presented for T. dentatus was 

 in Zerndt, 1932b, pi. 1, fig. 5, designated 

 at that time as type 24A. Later Zerndt 

 (1938a) noted that these are referred to 

 type 37, and (in Zerndt, 1938b) noted type 

 37 as T. dentatus Zerndt. 



The only apparent distinction between 

 the Illinois spores and those described by 

 Arnold and Dijkstra is that the Illinois 

 spores may have higher lips, but at present 

 this is not considered a basis for specific 

 distinction. The Illinois spores also are 

 similar, except for the sometimes greater 

 development of fingerlike processes, to 

 those of Triletes dentatus that Pierart 



(1957) describes as characteristic of the 

 Upper Westphalian C of the Belgian 

 Campine. 



Cross (1947, p. 287, fig. 2; pi. I, figs. 2, 3; 

 pi. Ill, figs. 84-86; p. 301) described spores 

 designated as Triletes rotatus from the 

 Powellton, Cedar Grove, Chilton, and Coal- 

 burg Coals of the Kanawha Group from 

 the Appalachian Basin. From his descrip- 

 tion it appears that many of the spores he 

 noted are of the T. rotatus type, but two 

 specimens that he illustrated (Cross, 1947; 

 pi. I, figs. 2, 3) are very similar to those 

 Dijkstra (1952b; pi. 5, figs. 1, 2, 6) illus- 

 trated and designated as T. dentatus. 



Occurrence. — Spores of Triletes ramosus 

 are most typically found in the older coals 

 of the Tradewater Group, but are sporadic 

 in distribution, and generally do not occur 

 in great quantities. A few spores, along 

 with some more typical of T. rotatus, were 

 found in the shale (maceration 163) above 

 the Pinnick Coal in Indiana. Thev are 

 abundant in the upper part of the Willis 

 Coal (maceration 625A) and common in 

 the lower part of the Willis Coal (macera- 

 tion 625B) and in the Willis (?) Coal 

 (maceration 631). They are rare in the 

 Tarter Coal (maceration 901), rare to 

 common in the Rock Island (No. 1) Coal 

 (macerations 929 and 626, respectively) , 

 and common in the upper part of the New 

 Burnside Coal (maceration 938A) . Rare, 

 badly preserved fragments, possibly refer- 

 able to this species, were found in one of 

 the lower coals (maceration 950A) from 

 Goose Lake and in an unnamed coal (mac- 

 eration 936) nine feet above the DeKoven 

 Coal. 



Triletes superbus Bartlett, 1929 



Plate 8, figures 7, 8; plate 9, figures 1, 2 



1929 Tritetes superbus Bartlett, p. 20-21; pi. VII, 

 figs. 1, 2; pi. VIII, figs. 1, 2. 



Description. — Megaspores large, trilete, 

 commonly compressed in proximo-distal 

 orientation, up to 4100 p in total diameter; 

 spore body round to subtriangular in out- 

 line, ranging from 1375 to 3260 ^ in diame- 

 ter (mean 1875 ^ for 14 specimens) . Trilete 

 rays very prominent; lips up to 400 ^ in 



