30 



PENNSYLVANIAN SPORES OF ILLINOIS 



wider, with a thicker spore coat and def- 

 inite lips. 



Laevigato-sporites pseudothiessenii sp. 

 nov. 



Plate 5, figure 10 



Description. — Spores are bilateral, mono- 

 lete, elongate to oval in the plane of 

 longitudinal symmetry, round or oval in 

 transverse plane. The outline in both 

 longitudinal and transverse planes is broken 

 by the sculpturing of the spore coat. The 

 holotype measures 37.8 X 29.4 microns. 

 The known size range is from 26 to 46 mi- 

 crons in the longitudinal plane. The orna- 

 mentation is various depending upon the 

 degree of maceration. In general, the spore 

 coat is verrucose to obvermiculate and some- 

 times appears reticulate. The monolete 

 tetrad mark extends well over half the 

 length of the spore. The spore varies in 

 thickness, due to ornamentation, from 1.5 

 to 3.5 microns. 



Holotype.— Maceration 543-D Slide 4, 

 No. 5 coal bed, Fulton County, Illinois. 

 The known range of the species is from the 

 Upper Tradewater (Dekoven coal bed) 

 to lower middle McLeansboro (upper 

 Scottville coal bed). 



Discussion. — L. pseudothiessenii is dis- 

 tinct from L. thiessenii due to larger size 

 and slight differences in ornamentation. 

 The two species are similar in many respects, 

 and are probably from closely related parent 

 plants. The writer has observed this 

 species from the middle Kittaning coal bed 

 in Ohio, the Mystic coal bed of Iowa, the 

 Tebo and Lexington coal beds from Mis- 

 souri, and in Indiana from No. VII coal 

 bed to No. Ill coal bed. Thiessen was the 

 first to observe and illustrate this species 

 (1932, page 22, figures 14 B-C). 



Laevigato-sporites punctatus sp. nov. 



Plate 5, figure 3 



Description. — Spores are bilateral, mono- 

 lete, oval to broadly bean-shaped in longi- 

 tudinal plane. Holotype measures 44 X 

 35.7 microns, and the known size variation 

 in the long axis is from 35 to 51 microns. 



The spore coat is distinctly punctate, the 

 monolete mark is over half the length of the 

 spore, and the lips are poorly developed. 

 The spore coat is 1.25 to 2 microns in thick- 

 ness. 



Holotype.— Maceration 625-A Slide 1, 

 Willis coal bed, Gallatin County, Illinois. 

 L. punctatus is known to occur from the 

 lower Tradewater throughout the Carbon- 

 dale. 



Discussion. — Spores of this type are at 

 the present assigned to the genus Laevigato- 

 sporites sp. nov. on the basis of the mono- 

 lete scar and because their symmetry is not 

 radial but bilateral. However, the sym- 

 metry is not as strongly bilateral as in most 

 other species of the genus. L. punctatus 

 may be distinguished from small forms of 

 L. vulgaris (Ibrahim) Ibrahim, 1933, on 

 the basis of a more sharply punctate orna- 

 mentation. 



Laevigato-sporites robustus sp. nov. 



Plate 5, figure 9 



Description. — Spores are bilateral, mono- 

 lete, broadly bean shaped. Small folds of 

 spore coat are common and occur almost 

 anywhere either proximally or distally. The 

 holotype measures 101.8 X 73.5 microns, 

 and the known size range is from 79.8 to 

 150 microns in the longest diameter where- 

 as the average range is from about 85 to 

 120 microns. The spore coat is distinctly 

 levigate, and the monolete mark is usually 

 one-half to two-thirds the length of the 

 spore. The lips are usually not distinct 

 and the suture is sometimes open. The 

 spore coat is 1.5 to 2 microns thick. 



Holotype. — Maceration 574 Slide 8, coal 

 bed below the Shoal Creek coal bed, Bond 

 County. 



Discussion. — -The size range of 79.8 to 

 150 in the longest diameter may well in- 

 clude at least two species based on size 

 range. However, it is necessary to name the 

 forms and it is doubtful that it will be 

 possible to delineate species properly until 

 spores of this type are found within repro- 

 ductive organs. Raistrick's type B may be 

 conspecific with L. robustus sp. nov. 



