38 



PENNSYLVANIAN SPORES OF ILLINOIS 



are radial, trilete, elliptical to oval in verti- 

 cal plane, subtriangular to triangular in 

 transverse plane. The interradial margin 

 varies from concave to convex. The spores 

 are usually compressed in good proximal- 

 distal orientation. Folding of the spore 

 coat is relatively rare, but folding or over- 

 lapping of the arcuate thickenings is com- 

 mon where the thickenings are pronounced. 

 The known size range is from 22 to 75 mi- 

 crons. The ornamentation of the spore 

 coat varies from levigate, granulose, mildly 

 punctate, verrucose, spinose, to blunt pro- 

 jections or processes. The trilete rays are 

 usually distinct and extend at least two- 

 thirds the distance to the margin of the 

 spore wall and in most species the rays ex- 

 tend three-fourths the distance. The lips 

 and commissure may be moderately devel- 

 oped or almost lacking. The spore coat is 

 characterized by extremes in variation due 

 to the universal presence of thickened cor- 

 ners opposite the rays. The spore coat, 

 exclusive of the thickened corners, varies 

 in thickness from 1 to 9 microns. The 

 parent plant of Triquitrites is unknown. 

 It is thought possible by Schopf, Wilson, and 

 Bentall (1944) to be related possibly to 

 the filicineans. It has been noted that an 

 increase in the abundance of prepollens 

 sometimes is associated with increase in the 

 abundance of Triquitrites. This may be 

 of ecological importance. 



The following are new species isolated 

 from Illinois coal beds: 



1. T. angulatus 



2. T. crass us 



3. T. discoideus 



4. T. inusitatus 



5. T. pulvinatus 



6. T. priscus 



7. T. protensus 



Triquitrites angulatus sp. nov. 



Plate 8, figure 8 



Description. — Spores are radial, trilete, 

 triangular in transverse plane, margin be- 

 tween rays is slightly concave or convex, 

 and the corners opposite the rays are ex- 

 tremely wide and thickened. The holo- 

 type measures 71.9 to 70.9 microns, and 



the known size range is from 66 to 75 mi- 

 crons. The arcuate thickenings are perhaps 

 the most extreme of any species of the genus, 

 and appear to be connected to each other 

 by a thickened line on the proximal surface. 

 The arcuate thickenings of the holotype 

 vary in length from 33 to 42 microns and 

 in width up to 8 microns. The ornamenta- 

 tion is levigate on both the proximal and 

 distal surfaces. The trilete mark is dis- 

 tinct, the lips are slightly elevated, and the 

 commissure is thin. The spore coat is 

 2.25 to 3.5 microns in thickness exclusive 

 of the arcuate thickenings. 



Holotype.— Maceration 520-A Slide 3, 

 Bald Hill coal bed, Williamson County, 

 Illinois. 



Discussion. — T. angulatus sp. nov. is the 

 largest species of the genus thus far ob- 

 served and is characterized by an unusual 

 development of the arcuate thickenings. 



Triquitrites crassus sp. nov. 



Plate 8, figure 6 



Description. — Spores are radial, trilete, 

 subtriangular in outline, interradial mar- 

 gins generally slightly convex, and have 

 arcuate thickenings. The holotype meas- 

 ures 66.1 X 67.2 microns, and the known 

 size range is from 61 to 73 microns. The 

 arcuate thickenings appear to originate on 

 the proximal surface and surround the 

 apex of the rays. The widest thickening 

 measured on the holotype was 14.7 microns, 

 and the length averaged 16.8 microns. The 

 spore coat is levigate with widely scattered 

 blunt projections on both proximal and 

 distal surfaces. The trilete rays are dis- 

 tinct, and extend at least three-fourths the 

 distance to the margin of the spore wall. 

 The lips are slightly elevated and the com- 

 missure is distinct. The spore coat varies 

 in thickness due to the projections; how- 

 ever, exclusive of the projections, the spore 

 coat ranges from 5.2 to 9 microns. 



Holotype.— Maceration 574 Slide 21, 

 Shoal Creek coal bed, Bond County, Illi- 

 nois. 



Discussion. — The thick spore coat and 

 projections help characterize T. crassus sp. 

 nov. 



