48 



ILLINOIS STATE GEOLOGICAL SURVEY 



the H. Forester No. 1 core, Perry County, 

 Illinois, and in a plant bed believed to be 

 near the base of the Glen Dean Formation 

 (maceration 888) at Big Stone Gap, Vir- 

 ginia. Spine fragments, possibly of this spe- 

 cies, were noted in the coal in the Vienna 

 Formation (maceration 687B) from John- 

 son County, Illinois. No positively identi- 

 fied fragments have yet been found in coals. 



Triletes eregliensis Dijkstra, 1952 



1952 Triletes eregliensis Dijkstra (1952a), p. 102- 

 103; pi. VII, fig. 3. 



Triletes cf. T. eregliensis 

 Plate 6, figure 6 



Discussion. — The three spores found have 

 equatorial dimensions of 940 ti, 1010 /x, and 

 1130^, respectively. They are matte brown 

 by reflected light, opaque by transmitted 

 light. Closely spaced, irregularly formed, 

 distal papillae, up to 25 ^ in length, give a 

 dark brown to black appearance to the dis- 

 tal coat. Although the ornamentation is 

 very similar to that shown by Dijkstra, 

 these three spores are smaller, have slightly 

 higher lips, and more prominent arcuate 

 ridges, especially at the juncture of the 

 ridges with the trilete rays. The ridges are 

 similar to a very thick, short flange, the 

 distal surface of which appears free of orna- 

 mentation. Two of the spores, although 

 partially torn apart, are still in tetrad asso- 

 ciation (pi. 6, fig. 6) . Immature spores 

 might be expected to have more prominent 

 ridges than mature spores. 



Dijkstra originally described Triletes 

 eregliensis — one complete spore and several 

 broken ones — from the Westphalian D of 

 Turkey. Pierart (1957) reports one small 

 specimen (720 ^) from the Upper West- 

 phalian C of Belgium. 



Occurrence. — These spores were found in 

 one sample of the Tarter Coal (maceration 

 604A) , Fulton County, Illinois. 



Genus Triletes? 

 Triletes? saturnipunctatus n. sp. 



Plate 10, figure 11 



Description. — Spores are rather small for 

 megaspores, originally somewhat oblate to 

 disk-shaped, rounded triangular in equa- 



torial outline, ranging from 325 to 440 p 

 in diameter (mean 400 ^ for 20 specimens) . 

 Trilete suture is distinct, generally open; 

 trilete rays extend more than two-thirds 

 the spore radius, possessing no labial devel- 

 opment. 



Spore coat is characterized by a robust 

 equatorial rim up to 60 ^ thick, apparently 

 consisting of two layers, a thin inner one 

 about 4 to 5 /x thick and a thick outer layer. 

 Thickness of spore coat at equator equals 

 as much as 10 to 16 percent of the total 

 spore diameter; diameter of inner spore 

 cavity (six specimens) equals 71 to 78 per- 

 cent of the total diameter. In side view, 

 the outer margin of equatorial rim is 

 rounded, occasionally sharp on poorly pre- 

 served spores. Spore coat thins to as little 

 as 5 fj, thick near proximal pole, decreases 

 gradually to 10 ^ thick at distal pole. Spore 

 coat is rarely folded, except for apical cor- 

 ners of contact areas. Worn specimens com- 

 monly lack central proximal surface, some 

 of them also lack central distal surface so 

 that only the dark circular rim remains. 



Spore coat is minutely but distinctly 

 punctate, dark reddish brown to yellow by 

 transmitted light, glossy and dark brown 

 by reflected light. 



Holotype. — Maceration 916 slide 5, Pope 

 Creek Coal (lower 4 inches), Mercer Coun- 

 ty, Illinois (pi. 10, fig. 11). 



Discussion. — Except for size, spores of 

 Triletes? saturnipunctatus are comparable 

 with the smooth-rimmed spores of Denso- 

 sporites and when seen in cross section 

 would have a similar dumbbell shape. The 

 outer surface of the spore coat is distinctly 

 but densely ornamented with tiny puncta. 

 When observed at magnifications less than 

 400 X, the puncta seem to be oriented in 

 convolute rows and cause the crinkled ap- 

 pearance of the spore coat. Proximo-distal 

 compressions are not always symmetrical in 

 outline but may be irregularly rounded tri- 

 angular or even compressed into an oval 

 outline if the thin proximal and distal sur- 

 faces are missing. 



These spores have a size range similar to 

 those referred to Bentzisporites bentzii Po- 

 tonie and Kremp (1954, p. 161, pi. 20, fig. 



