22 



ILLINOIS STATE GEOLOGICAL SURVEY 



Spore coat punctate or minutely meshed, 

 granulose on lips, 25 to 30 ^ thick, deep red- 

 dish brown to orange-brown by transmitted 

 light. Spines appearing light yellow and 

 smooth. 



Discussion. — The above description is 

 based on the few megaspores of this species, 

 occurring with abundant megaspores of 

 Triletes subpilosus forma major, found in 

 the coal in the Bethel (Mooretown) Forma- 

 tion (maceration 943) of Hardin County, 

 Kentucky. Similar megaspores are domi- 

 nant in the same coal (macerations 832, 

 834) of Lawrence County, Indiana, but oc- 

 cur in equal abundance with megaspores of 

 T. subpilosus forma major in the same coal 

 (maceration 468) of Washington County, 

 Indiana. Megaspores of T. crassiaculeatus 

 of these Indiana coals are identical to those 

 in the coal from Kentucky, but range up to 

 1860 jit in equatorial diameter and possess 

 spines as long as 350 /x. 



These Triletes crassiaculeatus spores are 

 similar in most respects to those originally 

 described by Zerndt (1937a) except that the 

 spines are generally not pointed but ball- 

 tipped and the spore coat is thinner than 

 the 48 fx thickness given by Zerndt. They 

 also are similar in over-all size, shape of 

 apical prominence, and in the possession of 

 spines of varying lengths, to those of Lage- 

 nicula I var. major Bennie and Kidston 

 (1886, figs. 20e, 20f, 20n) which occur abun- 

 dantly at their locality 1, the basal beds of 

 the Calciferous Sandstone Series in Scot- 

 land. However, the spores from Illinois 

 generally possess a more dense investiture 

 of spines, and these spines may be fluted 

 basally rather than expanded and bulbose. 

 One spine on plate 3, figure 3, shows the 

 extreme development of the fluted spine 

 base. Some of the other spines on the same 

 spore tend to be more bulbose basally and 

 approach more closely the spine configura- 

 tion considered typical of T. crassiaculea- 

 tus. 



The spores from Kentucky and Indiana 

 generally are comparable with those Tri- 

 letes crassiaculeatus-type megaspores found 

 by Chaloner (1953b) in Lepidostrobus al- 



lantonensis. Chaloner also noted the pres- 

 ence of enlarged globular spine tips. 



The presence of forked spines has not 

 been noted in previous descriptions of typi- 

 cal lageniculate megaspores. In the posses- 

 sion of forked spines, spores of Triletes 

 crassiaculeatus are similar to some of the 

 extremely high apexed atypical lageniculate 

 spores of early Mississippian age (compare 

 with Chaloner, 1954b, pi. I, figs. 5, 6). 



Affinity. — Triletes crassiaculeatus-type 

 megaspores have been found in Lepidostro- 

 bus allantonensis (Chaloner, 1953b), in sed- 

 imentary association with Lepidodendron 

 nathorsti Kidston. Dijkstra (1952b) re- 

 ported the occurrence of this megaspore in 

 close association with Lepidodendron acu- 

 minatum. 



Previously Reported Occurrences. — Meg- 

 aspores of Triletes crassiaculeatus have been 

 reported from the "Randschicten" (Dinan- 

 tian or Namurian A) of Upper Silesia by 

 Zerndt (1937a), from the Namurian A 

 (abundant occurrence) and B of Turkey by 

 Dijkstra (1952b), and from the Calciferous 

 Sandstone Series (Dinantian) of Scotland 

 by Chaloner (1953b). 



Occurrence. — During this investigation 

 megaspores of Triletes crassiaculeatus were 

 found only in a coal in the lower part of 

 the Chester Series, in the Bethel (Moore- 

 town) Formation (macerations 943, 832, 

 834, 468) of Kentucky and Indiana. 



Triletes rugosus (Loose) Schopf, 1938 



(sensu Dijkstra, 1946) 



Plate 3, figures 4-9 



1932 Sporonites rugosus Loose, in Potonie, Ibra- 

 him, and Loose, p. 452; pi. 20, fig. 59. 



1933 Laevigati-sporites rugosus (Loose) Ibrahim, 

 p. 18-19; pi. 7, fig. 65. 



1934 Punctati-sporites rugosus (Loose) Loose, p. 

 146. 



1938 Triletes (?) rugosus (Loose) Schopf, p. 29- 



30; pi. 5, fig. 6. 

 1938 Triletes translucens Schopf, p. 28-29; pi. 1, 



fig. 12; pi. 5, figs. 3-5. 

 1944 Triletes rugosus (Loose) Schopf, in Schopf, 



Wilson, and Bentall, p. 25. 

 1946 Triletes rugosus (Loose) Dijkstra, p. 47-48; 



pi. 9, figs. 83-99; pi. 10, figs. 100-114; pi. 11, 



fig. 115. 



