ENDOSPORITES 



45 



surface. The spore body is less definitely 

 ornamented although the bladder pattern 

 may appear superimposed on it. Emphytic 

 ornament seems to be the same for proxi- 

 mal and distal surfaces. 



Haptotypic features. — Trilete rays com- 

 monly extend to the periphery of the 

 spore body and thickened continuations 

 from them may carry on to the bladder 

 membrane. The lips are oftentimes up- 

 raised and definite, the suture line distinct. 

 Sometimes a thickening is present on the 

 bladder membrane which corresponds to 

 arcuate ridges. 



Spore coat. — The bladder (perisporal) 

 membrane is quite thin and translucent ; 

 its reticulation tends to add somewhat to 

 the thickness as seen in marginal profile. 

 The body wall is substantially thicker al- 

 though also quite translucent, and cor- 

 responds to the exosporal layer. In a 

 few instances thin membranous, almost 

 hyaline, endosporal membranes have been 

 observed within the exospore and shrunk- 

 en from it. The suture lines are not dis- 

 tinct on these, but three clear-cut endo- 

 sporal apical papillae occur at the juncture 

 of pyramic apices. 



Affinities. — Endosporites is related to 

 some of the Pennsylvanian Cordaitaleans. 

 They correspond to spores observed by 

 Wilson in male strobili, and Schopf has 

 found well preserved specimens in such 

 abundant association with Cordaitean 

 leaves, other plant fossils being infrequent, 

 that no other conclusion seems permis- 

 sible. It should be emphasized, however, 

 that the pollen grains Florin (1936) 

 described in Cordaianthus fructifications 

 obtained from the French Stephanian are 

 evidently generically distinct and of more 

 advanced structure. 



Raistrick's types C-^ and C4 without 

 much question belong to Endosporites 

 (Raistrick and Simpson, 1933; Knox, 

 1938). Type 629 of Reinsch (1884, p. 61, 

 pi. 48, fig. 252A) from the Blatterkohle 

 and Stigmarienkohle of Metschowk (in 

 central Russia) and probably others less 

 easy to interpret from his drawings, also 

 belongs to Endosporites. 



Remarks. — The distended bladder mem- 

 brane is the most characteristic feature 

 of certain gymnospermous pollen grains. 

 The expansion of the bladder is various 

 in the several groups which are known as 



Parasporites, Cordaianthus, Alisporites, 

 Caytonanthus, Pityosporites and Endo- 

 sporites, as well as in modern podocarps 

 and Abietineae. There is good reason to 

 believe that bladders of this type are ho- 

 mologous structures, which may have un- 

 dergone progressive and regressive de- 

 velopment at various times within the 

 broad confines of this alliance, but 

 nevertheless largely preserve their iden- 

 tity throughout. 



Endosporites shows such evident de- 

 velopment of proximal haptotypic struc- 

 tures that gametophytic exit was quite 

 evidently from the proximal pole as in 

 the cryptogams. Florin, working with 

 excellently preserved silicified material, 

 has shown that in some late Pennsylvanian 

 (Stephanian) forms the haptotypic fea- 

 tures were vestigial and in mature forms 

 present only as a surface imprint on the 

 bladder membrane which does not even 

 maintain contact with the spore body. 

 The bladder and body are in contact dis- 

 tally, however, and prothallial cells line 

 the body cavity except at this point. Thus 

 in these advanced forms germinal exit 

 must have been distal as it is in pollen of 

 all modern conifers. Pollen-like types of 

 this sort having indication of proximal 

 exit have been termed *'prepollen," fol- 

 lowing Renault, and its significance has 

 been discussed elsewhere (Schopf, 1938; 

 pp. 14 and 15, 48). Endosporites male 

 spores are evidently prepollen in this 

 sense. 



Eight previously described species are 

 listed below, only one of which is queried. 

 The genus is widely distributed both in 

 America and in Europe. The genotype 

 species, E. ornatus Wilson and Coe, is 

 from Iowa coal of Des Moines age. 



1. Endosporites angulatus Wilson and Coe, 

 1940, Am. Midland Naturalist, vol. 23, no. 

 1, p. 184, fig. 1. 



2. Endosporites globiformis (Ibrahim) S. 

 W. and B., comb. nov. 



Sporonites globiformis Ibrahim, 1932, 

 Neues Jahrb., Beilage-Band 67, Abt. B, p. 

 447, pi. 14, fig. 5. 



Zonales-sporites globiformis (Ibrahim) 

 Ibrahim, 1933, Sporenformen des Aegir- 

 horizonts, p. 28, pi. 1, fig. 5. 



Zonales-sporites globiformis (Ibrahim) 

 Ibrahim, Loose, 1934, Inst. Palaobot. Arb., 

 vol. 4, no. 3, p. 148. 



3. Endosporites (?) karczewskii (Zerndt) 

 S. W. and B., comb. nov. 



