GENUS CALAMOSPORA 



59 



However, none of the specimens here re- 

 ferred to S. cf. S. gracilis possesses radially 

 striated contact surfaces. Such surfaces are 

 shown only by spores found in the Rock 

 Island (No. 1) Coal and older coals 

 whereas those with anastomosing folds 

 rather than radial striations on the contact 

 areas are found only in younger coals. 



The marginal flange on spores of the 

 Reynoldsburg Coal (maceration 618) ac- 

 counts for 9 to 18 percent (mean 13.5 per- 

 cent) of the total diameter; the same spores 

 have well defined contact area striations. 

 The marginal flange on spores from the 

 DeKoven Coal (maceration 519A-B) ac- 

 counts for 11 to 19 percent (mean 15.7 

 percent) of the total diameter. None of 

 these spores has contact area striations. On 

 spores from some of the McLeansboro coals 

 the marginal flange accounts for 10 to 28 

 percent (mean 21 percent) of the total 

 diameter. 



The spores to which these Illinois spores 

 are compared were originally described by 

 Zerndt (1937b) from the Westphalian E 

 (Stephanian) of Bohemia. 



Occurrence. — This species is represented 

 in the Wiley (maceration 525A) , Davis 

 (maceration 518B), and DeKoven (macer- 

 ation 519A-B) Coals from the upper part 

 of the Tradewater Group. These spores are 

 fairly common in the lower part of the De- 

 Koven Coal. In the Carbondale Group the 

 spores are rare in the Colchester (No. 2) 

 Coal (maceration 580) , rare to common in 

 the No. 5 Coal (macerations 630, 879, re- 

 spectively) , and present in the Briar Hill 

 (No. 5a) Coal (maceration 633A) . 



In the McLeansboro Group spores of 

 this species are rare in a Friendsville Coal 

 (maceration 490D) , in the "LaSalle" Coal 

 (maceration 600) , and in a coal bed desig- 

 nated as the "Divide" Coal (maceration 

 811). In the Illinois State Geological Sur- 

 vey maceration records, their presence has 

 been noted in coal beds designated as "Bo- 

 gota," "Newton," Shelbyville, and Trow- 

 bridge, mainly from Effingham, Fayette, 

 and Shelby Counties, Illinois. Many of 

 these have been checked as to their identity 

 with Spencerisporites cf. S. gracilis. They 

 are common to abundant and well pre- 



served in the "Bogota" Coal (maceration 

 133), an upper McLeansboro coal in 

 Illinois. 



Genus Calamospora Schopf, Wilson, 

 and Bentall, 1944 



Type species. — Calamospora hartungiana Schopf, in 

 Schopf, Wilson, and Bentall, 1944, by their 

 designation. 



Description. — Spores of Calamospora are 

 trilete and radially symmetrical. Their 

 original shape is more or less spherical, so 

 that when compressed, they develop char- 

 acteristic taper-point folds of crescentic or 

 lenticular outline. Spore size may range 

 from 30 to several hundred microns. Horst 

 (1955) extended the upper size limit to 

 more than 1000 p. Trilete rays are generally 

 short, less than one-half the spore radius in 

 length. Lips may be present. Contact areas 

 may show some differentiation of the spore 

 coat in surface texture or thickening. Spore 

 coat thickness ranges from more than 15 /x 

 in spores larger than 500 p in diameter to 

 less than 2 p in those less than 100 jX in di- 

 ameter. The coat is characteristically 

 smooth and highly refractive. 



Discussion. — Only the larger spores of 

 Calamospora, undoubtedly megaspores, are 

 described in this paper. The smaller mega- 

 spores appear to have a long stratigraphic 

 range, occurring throughout the Pennsyl- 

 vanian in Illinois; the large megaspores 

 (C. cf. C. sinuosa) seem to be restricted to 

 older coal beds of the Tradewater Group. 



Affinity. — These spores are of sphenopsid 

 alliance and may be borne by plants of the 

 Sphenophyllales, Equisetales, and Noegge- 

 rathiales. Calamospora is unique among 

 taxa based on spores, in that isospores, mi- 

 crospores, and megaspores are included 

 within it. 



Occurrence. — Only one poorly preserved 

 megaspore, questionably referable to Cala- 

 mospora, was found in coals of upper Mis- 

 sissippian age. Megaspores referred to C. 

 laevigata are present in many of the Penn- 

 sylvanian coals; those referred to C. sinuosa 

 occur only in the older coals of the Trade- 

 water Group. In addition, a few specimens, 

 indeterminable on the specific level, were 

 found in the Rock Island (No. 1) Coal 



