GENUS TRILETES 



35 



height, generally highest at apex and ex- 

 tremities. Upper margin of lips in some 

 specimens ornamented with spine-like pro- 

 jections, somewhat fluted and sinuous. 

 Contact surfaces smooth to tuberculate. 

 Small spines up to 30^ in length and 10^ 

 in diameter may extend from tubercles (pi. 

 8, fig. 7) . 



On well preserved specimens distal sur- 

 face ornamented with processes 35 to 145 ^ 

 in length, 10 to 15 ^ in minimum diameter, 

 of maximum length immediately distal to 

 distinctive marginal flange. Distal processes 

 generally parallel-sided and rounded or 

 blunt to distinctly club-shaped terminally. 

 Flange elements arising from encircling 

 rows of slender bases in a zone extending 

 both proximal and distal to geometrical 

 equator; processes anastomosing outward 

 forming an irregular fenestrate flange, 

 probably thick, honeycomb-like, and deli- 

 cate when uncompressed; flange 410 to 

 1040^ wide, widest opposite ends of trilete 

 rays. Denuded spores possess tubercles in 

 the flange attachment zone. Spore coat 41 

 to 51 fx thick. Well preserved specimens 

 dull brown with glossy brown to amber 

 ornamentation by reflected light. 



Discussion. — These megaspores seem to 

 be identical to those originally described by 

 Bartlett (1929) in regard to distal orna- 

 mentation and flange development, but 

 some specimens are smaller than the mini- 

 mum size given by him. However, most 

 fall within the size range given by later 

 authors. One spore, 3260 ^ in body diame- 

 ter and 4100^ in total diameter, is one of 

 the largest recorded for the species. These 

 spores also are similar to those described 

 by Dijkstra (1955a) as Triletes brasserti 

 forma 1. His description of the configura- 

 tion of the flange implies a much closer re- 

 lationship to spores of T. superbus Bartlett 

 than to those originally described as T. 

 brasserti by Stach and Zerndt (1931) . On 

 the other hand, his description of T. bras- 

 serti forma 2 is quite similar to that given 

 here for spores referred to T. brasserti. 



Previously reported occurrences of these 

 spores are in the Westphalian B-D of Eu- 

 rope (Dijkstra, 1952b; Potonie and Kremp, 

 1956) . They were originally described by 

 Bartlett from coal pebbles found in the 



glacial drift near Ann Arbor, Michigan. 

 < Iross (1947, p. 287, fig. 2; p. 300; pi. I, fig. 

 1; pi. Ill, figs. 62-65) reported their occur- 

 rence in the Winifrede and Coalburg Coals 

 from the upper part of the Kanawha Group 

 of the Appalachian Basin. Although Chal- 

 oner's (1956a) T. supcrbus-type mega- 

 spores are from a cone compression pre- 

 sumably from the lower part of the 

 Carbondale Group above Colchester (Xo. 

 2) Coal, spores of T. superbus are most 

 common in coals of the Caseyville and 

 lower Tradewater Groups. 



Affinity. — In comparison with the mega- 

 spores of the Triletes superb us-type that 

 Chaloner (1956a) found in Sporangiostro- 

 bus langfordi Chaloner, these Illinois 

 spores are similar in most respects except 

 that the lips have not been observed to be 

 as high as 760 ^ Sporangiostrobus is as- 

 sumed to have been borne by arborescent 

 lycopods similar to Lepidodendron or Sigil- 

 laria (Chaloner, 1956a) . 



Occurrence. — Spores of Triletes superbus 

 are common in the "Makanda" Coals 

 (macerations 906, 142) . They are rare in 

 the Pinnick Coal (maceration 150), but 

 common to abundant in the shale (macera- 

 tion 163) above the Pinnick Coal and in 

 the Cannelton Coal (maceration 780) of 

 Indiana. They are rare in a Caseyville age 

 coal (maceration 910) of Illinois, and also 

 are rare in the Jagger Coal of the Warrior 

 Basin of Alabama. In both the "Makanda" 

 Coals (maceration 906) and in the shale 

 above the Pinnick Coal these spores occur 

 in large masses and in tetrad association. 



In the Tradewater Group, they are com- 

 mon in the "Sub-Babylon" Coal (macera- 

 tion 144) and rare in the upper part (mac- 

 eration 625A) of the Willis Coal and in 

 the Rock Island (Xo. 1) Coal (maceration 

 929) . Some poorly preserved specimens 

 were found in one of the lower coals (mac- 

 eration 950) from Goose Lake, Illinois. 



Triletes brasserti Stach and Zerndt, 1931 



Plate 9, figures 3-10; text figure 3 



1931 Triletes brasserti Stach and Zerndt. p. 1123; 

 figs. 28-31. 



Description. — Spores of medium to large 

 si/e, trilete, showing no preferred compres- 



