OTHER MICROFOSSILS 



67 



OTHER MICROFOSSILS OF THE PLUS 

 65-MESH RESIDUES 



Plant spores are not the only microfossils 

 found in macerated coal residues. Other 

 microfossils, such as fragments of cuticle 

 that may bear the impressions of the orig- 

 inal underlying epidermal cell structure, 

 seed membranes, resin blebs and rodlets, 

 sporangial masses of small spores, or woody 

 fragments, are abundant constituents of 

 some residues. 



Some papers that are specifically devoted 

 to seed membranes (Arnold, 1948; Schemel, 

 1950b) have been published in this coun- 

 try. Harris (1956) has recently emphasized 

 the importance of the study of fossil cuticle. 

 Brief mention is given below to some of the 

 various types of plant and animal (?) mi- 

 crofossils that were encountered during this 

 study. 



Sporangial masses of Densosporites 

 Plate 15, figures 6, 7 



Two ovoid sporangial masses, enclosed in 

 a thin membrane, were picked from the 

 maceration residue of the Tarter Coal 

 (maceration 604A) . The more or less com- 

 plete specimen (pi. 15, fig. 6) is about 

 4200 /a in over-all dimension. The broken 

 specimen, about 2900 ^ in length, was dis- 

 sected and found to contain a mass of spores 

 similar to those of Densosporites lobatus 

 Kosanke. These spores also were seen at 

 the margins of the complete specimen. 

 Somewhat smaller, but empty, sporangial 

 sacs showing cell patterns similar to that 

 illustrated by figure 7 on plate 15 were seen 

 in prepared slides of the shale (maceration 

 163) above the Pinnick Coal of Indiana. 



Abundant spores of Densosporites loba- 

 tus were associated with the sacs, but their 

 origin in the sacs is not demonstrable as 

 it is with those from the Tarter Coal. Of 

 course, many sporangial masses of other 

 kinds of small spores, such as Schulzospora 

 in the Mississippian and early Pennsyl- 

 vanian, also were noted, but Densosporites 

 masses are described here because the 

 spores commonly are not found in masses 

 and little was known of their affinity until 

 the recent discovery of this type of spore in 



the lycopod cone Selaginellites canonbiensis 

 Chaloner (1958a). 



Seed Membranes 



Plate 15, figures 8-10; plate 16, figures 1, 2 



Seed membranes are present in many 

 coals, but are especially abundant in the 

 coal in the Tar Springs Formation, the 

 "Sub-Babylon" Coal, and in one of the im- 

 pure coals from a sinkhole deposit. Some 

 of the seed membranes from the coal in the 

 Tar Springs Formation are extremely large 

 (pi. 15, fig. 9), and some have well pre- 

 served apical caps (pi. 15, fig. 10) . Large 

 seed membranes also are present in the coal 

 in the Bethel (Moore town) Formation. 

 Although the one shown from the Willis 

 Coal (pi. 16, fig. 1) is well preserved, the 

 folds have obscured details of the apical 

 portion. Membranes like that shown in 

 figure 2 on plate 16 are fairly common in 

 McLeansboro coals. 



One of the most conspicuous seed mem- 

 branes is illustrated in figure 8 on plate 15. 

 Many of these membranes, very similar to 

 those described as Spermatites reticulatus 

 by Arnold (1948), occur throughout the 

 Pennsylvanian. They were not noted in 

 coals of upper Mississippian age or in those 

 that were studied from the Warrior Basin. 

 In the Caseyville Group they occur in the 

 Wayside (maceration 609) , Battery Rock 

 (macerations 908, 909) , and Reynoldsburg 

 (maceration 618) Coals and in an un- 

 named coal (maceration 798) . In the 

 Tradewater Group they occur in the Baby- 

 lon (maceration 145A-B) , Willis (macera- 

 tion 625A-B) , Pope Creek (maceration 

 916), Rock Island (No. 1) (macerations 

 528B, 599B) , New Burnside (maceration 

 938C) , Murphysboro (?) (maceration 

 628B) , Bald Hill (maceration 520A) , and 

 Wiley (maceration 525A-B) Coals. 



In the Carbondale Group they occur in 

 the Colchester (No. 2) (macerations 824, 

 603C) and Briar Hill (No. 5a) (macera- 

 tion 633A) Coals. In the McLeansboro 

 Group they occur, sometimes commonly, in 

 the Indiana VII (?) (maceration 939A), 

 "West Franklin" (maceration 831A-B), 

 "LaSalle" (maceration 600), Friendsville 



