GENUS RAISTR1CK1A 



47 



range is from 54 to 67 microns. The tri- 

 lete rays are very long, at least three-fourths 

 of the distance to the margin of the spore 

 wall. The lips are poorly developed. Many 

 specimens are torn along the rays and are 

 variously folded. Compressed forms rare- 

 ly show good proximal-distal orientation. 

 The many spines are often wider midway 

 from their base to the apex. Although they 

 taper toward the apex, they are not sharply 

 pointed. The spines are numerous, closely 

 spaced, and range in length from 7.7 to 

 9.5 microns. The maximum width at their 

 thickest portion does not exceed 4 microns. 

 The spore coat ranges in thickness from 

 more than 2 microns to less than 3.5 mi- 

 crons. 



Holotype.— Maceration 544 Slide 9, No. 

 7 coal bed, Fulton County, Illinois. 



Discussion. — R. crinita sp. nov. is charac- 

 terized by long rays roundly triangular in 

 transverse plane, and numerous closely 

 spaced spines which taper to a blunt point. 



Raistrickia crocea sp. nov. 

 Plate 11, figure 6 



Description. — Spores are radial, trilete, 

 round in transverse plane, and have 

 scattered ribbon-like projections which are 

 minutely partate at the apex. The holotype 

 spore body dimensions are 69.3 X 73.5 and 

 the known size range is from 63 to 77 mi- 

 crons. The trilete rays are not usually 

 sharply defined, and the rays average 

 about 23 microns in length. The lips 

 and commissure are thin and not greatly 

 developed. The ribbon-like projections are 

 11.5 X 15.7 microns in length and from 7.3 

 to 9.4 microns in width. The projections 

 are flattened, and occasionally twisted. 

 The apex of each projection is partate, 

 giving rise to as many as 6 spines measuring 

 slightly over a micron in length and about 

 half a micron in width. The spore coat 

 is thin, yellow, usually not more than 2 

 microns thick, and it is frequently folded 

 parallel to the periphery of the spore coat. 



Holotype. — Maceration 603-C Slide 1, 

 No. 2 coal bed, Fulton County, Illinois. 



Discussion. — R. crocea sp. nov. is related 

 to the other partate spine species of Rais- 



trickia. The spines differ from those of the 

 other species in that they are ribbon-like in 

 appearance. 



Raistrickia imbricata sp. nov. 

 Plate 11, figure 8 



Description. — Spores are radial, trilete, 

 roundly triangular to oval in transverse 

 plane, and have numerous imbricating 

 bluntly pointed spines. The overall dimen- 

 sions of the holotype are 56.7 X 67.2, and 

 the known size range is from 54.1 to 68.3 

 microns. The trilete rays are distinct 

 even though occasional spines overlap the 

 rays. The rays of the holotype vary in 

 length from 13 to 18 microns. The lips 

 are clearly visible and slightly elevated. 

 The commissure is usually thin but def- 

 inite. The spore coat is densely covered 

 with many bluntly pointed spines which 

 vary in length from 3 to 6.5 microns and 

 in width from 2 to 4.2 microns. The spore 

 coat is 2 to 3 microns thick, rarely folded 

 although the spines are frequently folded. 



Holotype.— Maceration 500-D Slide 3, 

 No. 6 coal bed, Wabash County, Illinois. 



Discussion. — R. imbricata sp. nov. is 

 characterized by numerous bluntly pointed 

 spines. 



Raistrickia irregularis sp. nov. 

 Plate 11, figure 5 



Description. — Spores are radial, trilete, 

 subtriangular in transverse plane, and have 

 blunt spines which appear to be somewhat 

 irregular in width. The holotype overall 

 dimensions are 71.4 X 71.4 microns, and 

 the known size range is from 66 to 77 mi- 

 crons. The trilete rays are distinct and 

 long, measuring from 21 to 28 microns in 

 length. The lips are moderately thick and 

 elevated. The commissure is usually clear- 

 ly demarcated. The blunt spines vary in 

 length from 4.4 to 7.2 microns and in 

 width from 3.1 to 10.5 microns. The spore 

 coat varies in thickness from 3 to 4 microns. 



Holotype.— Maceration 603-B Slide 6, 

 No. 2 coal bed, Fulton County, Illinois. 



Discussion. — R. irregularis sp. nov. is 

 characterized by long rays, and blunt spines 



