GENUS TR1LETES 



49 



109; 1955, pi. 7, figs. 48, 50; 1956, p. 124) 

 from the Upper Westphalian B and Lower 

 Westphalian C of the Ruhr Basin. Potonie 

 (1954a, p. 115) referred these spores to the 

 Selaginellales — herbaceous lycopods. Al- 

 though the spores of Triletest saturnipunc- 

 tatus apparently possess a much thicker de- 

 velopment of the coat in the equatorial re- 

 gion than do spores of B. bentzii, the rela- 

 tionship of the two species may be closer 

 than is now suspected. 



The spores fall within the size range of 

 megaspores, but whether or not they func- 

 tioned as megaspores is unknown. Their al- 

 liance with the genus Triletes is also in 

 question, as there is evidence neither for nor 

 against a lycopodiaceous alliance. 



Occurrence. — Triletes? saturnipunctatus 

 is common in the lower part, but rare in the 

 upper part, of the Pope Creek Coal (macer- 

 ations 916, 918) from Mercer County, Illi- 

 nois, near the type locality of the Pope 

 Creek Cyclothem. The spores have not 

 been found yet in samples of Pope Creek 

 Coal from other localities. 



Triletes? corycilis n. sp. 

 Plate 11, figures 1-3 



Description. — Megaspores trilete, origin- 

 ally spherical or slightly elongate and sac- 

 like, generally laterally compressed and 

 oval in outline, from 720 to 1 350 ^ in total 

 length (mean 11 00 /a for 10 specimens) and 

 from 670 to 11 10 /a in width (mean 840 ti 

 for 10 specimens) . Trilete suture well de- 

 fined, generally open; contact areas small 

 in proportion to total spore size with slight- 

 ly raised arcuate ridges. Trilete rays from 

 110 to 270 fx in length; contact areas from 

 150 to 310 jx in radial dimension. Contact 

 surfaces darker and in some specimens 

 thicker than distal spore coat, characterized 

 by a centrally located quadrant-shaped scar 

 75 to 120 fi in maximum dimension (pi. 11, 

 fig. 3) . The contact area in some speci- 

 mens covered by what appears to be a tri- 

 radiate "cap" (pi. 11, fig. 2) that extends 

 outward from spore in a ragged membra- 

 nous ridge at the arcuate ridge and along 

 rays (pi. 11, fig. 2) . Contact area scars not 

 as noticeable when cap is present. 



Spore coat about 5 to 10^ thick, granu- 

 lose to minutely fibrous, in some specimens 

 appearing much darker and rough-surfaced 

 at the distal pole; coat in area of contact 

 surface darker, about 8 to 10^ thick. 



Holotype. — Maceration 798 slide 10, low- 

 est coal in a diamond drill core from the 

 Caseyville Group, Wabash County, Illinois 



( P i. ii, % i). 



Discussion. — The dimensions given for 

 the total length, and especially the width, 

 are somewhat approximate because of the 

 modified spore shape caused by extensive 

 folding of the spore coat. 



The contact area cap is an unusual mor- 

 phologic feature and at present its origin is 

 not known. When it is present, the char- 

 acteristic contact area scars generally are 

 not noticeable. The caps could be the con- 

 tact surfaces torn from the sister spores of a 

 tetrad. 



In shape and in the possession of a some- 

 times dark and rough distal area, the spores 

 resemble those of Cystosporites. The coat, 

 however, is not plainly fibrous, but can ap- 

 pear minutely fibrous as does the coat of 

 some spores of C. verrucosus. No abortive 

 or immature spores of Triletes? corycilis 

 have been recognized. These spores also 

 resemble some of the lageniculate spores in 

 general body outline except that they do 

 not have an expanded apical prominence. 

 The shape is also similar to that of some 

 seed membranes. Although some membra- 

 nous cuticular material bearing cell wall im- 

 pressions was seen adhering to some speci- 

 mens, its organic connection could not be 

 proved. These microfossils are distinctly 

 trilete and must have originated in a tetra- 

 hedral tetrad. It seems unlikely that these 

 spores are merely the inner membrane of 

 other larger spores. 



At present their lycopodiaceous nature is 

 not proved and therefore their reference to 

 the genus Triletes is in question. 



Occurrence. — Megaspores of Triletes? 

 corycilis are common in and apparently re- 

 stricted to the oldest Pennsylvanian coals in 

 Illinois and Indiana, the lowest coal (mac- 

 eration 798) from a diamond drill core in 

 Wabash County, Illinois, and the French 



