MIDDLE DEVONIAN COAL IN ILLINOIS 9 



Following oxidation of the three samples in Schulze' s solution (1 part 

 saturated potassium chlorate solution to 2 parts concentrated nitric acid) for about 

 5 days, the liquid was neutralized by repeated changes of water. Treatment with 

 5 percent solution of potassium hydroxide for about 10 minutes was used to free 

 the spores from the other constituents. 



When the humic matter had been completely removed, the residue was sieved 

 through a 65 -mesh Tyler screen with openings of 210 \± to remove the coarse frag- 

 ments. A portion of the fine fraction was dehydrated in alcohol and a 50 percent 

 alcohol -5 percent xylol solution and mounted with liquid Canada balsam on mi- 

 croscope slides for examination. A Spencer Microstar microscope (serial no. 417297) 

 was used for locating by coordinates the individual spores on the slides. All 

 slides are deposited in the Illinois State Geological Survey paleobotany collection. 



DESCRIPTIVE PALYNOLOGY 

 Plant Spores 



Genus PUNCTATISPO RITES (Ibrahim) Potonie and Kremp, 1954 

 Type species. — P. punctatus (Ibrahim) Potonie and Kremp, 1954. 



Punctatisporites solidus Hacquebard, 1957 

 Plate 3, figure 1 



Discussion. — Except for the slightly more circular outline of the two speci- 

 mens observed in this investigation, they conform to the description and illustra- 

 tion of this species given by Hacquebard. 



Punctatisporite s glaber (Naumova) Playford, 1962 

 Plate 3, figure 2 



Punctatisporites cf. irrasus Hacquebard, 1957 

 Plate 3, figure 3 



Discussion. — Hacquebard (1957, p. 308) reported a size range of 67 to 83 \± 

 for P. irrasus , but Sullivan (1964, p. 1251) and Doubinger and Rauscher (1966, 

 p. 366) included spores with a minimum size limit of 56 and 52 [x, respectively. 

 The maximum dimension of the Illinois specimen is 61.8 \±. 



Punctatisporites aerarius Butterworth and Williams, 1958 

 Plate 3, figure 4 



Punctatisporites sp. 

 Plate 3, figure 5 



