TRILETES 



19 



dominant. Evidence of the affinity of 

 these spores is shown by every spore- 

 containing- megasporangiate fructification 

 of the free-sporing lycopsids of this pe- 

 riod. Unfortunately, this corollary in- 

 formation has not always been considered 

 in fossil spore classification and additional 

 genera have been proposed which are in 

 conflict with Triletes. The types of these 

 subsequently defined and consequently un- 

 tenable genera are listed below. They are 

 also included in alphabetical position in the 

 main list of species with their synonymic 

 citations. 



Triletes reinschi (Ibrahim) Schopf (1938), 

 which also is the type species by designa- 

 tion for Triletes. (Type of Laevigati- 

 sporites Ibrahim 1933). 



Triletes tuberosus (Ibrahim) S. W. and B., 

 comb. nov. (Type of Tiiberculati-sporites 

 Ibrahim, 1933). 



Triletes sextus S. W. and B., nomen nov. (As 

 Triletes VI of Bennie and Kidston (1886), 

 this form was regarded as the type of 

 Apiculati-sporites Ibrahim, 1933). 



Triletes hirsutus (Loose) S. W. and B., comb, 

 nov. (Type of Setosi-sporites Ibrahim, 

 1933). 



Triletes sextusdecimus S. W. and B., nomen 

 nov. (As Triletes XVI of Bennie and 

 Kidston (1886), this form was regarded 

 as the type of Zonales-sporites Ibrahim, 

 1933). 



Triletes trilobus (Ibrahim) S. W. and B., 

 comb. nov. (Type of Valvisi-sporitcs Ibra- 

 him, 1933). 



By no means all the species that authors 

 regarded as congeneric with these types by 

 virtue of arbitrary (artificial) distinctions 

 appear so when broader comparisons are 

 attempted. This is particularly true of 

 the smaller forms (isospores and micro- 

 spores) which often have been denomi- 

 nated indiscriminately. These forms have 

 of course been reallocated to what have 

 the appearance, at least, of constituting 

 more natural groups. 



The following is a list of described 

 species of Triletes as the genus is now 

 conceived. Some forms listed here may 

 be so closely related to one another that 

 in later studies the names will be con- 

 sidered as synonyms. Without consulta- 

 tion of the types or specimens correspond- 

 ing to them these questions as to actual 

 synonymy appear to be unsolvable. W^icher 

 ( 1934) has placed several of these names 

 in synonymous relationship, and in all 

 probability correctly, since many of the 

 poorly illustrated holotypes were available 



to him for examination. It may be like- 

 wise a matter of individual opinion as 

 to whether certain holotypes are conspe- 

 cific. Such questions tend to be academic 

 because there can be no doubt that the 

 relationship is close in these instances. 

 Also, whether the forms are distinguished 

 as species or as varieties may be a matter 

 of individual taxonomic policy. We have 

 made as few changes of status as seemed 

 reconcilable with a uniform taxonomic 

 practice. Inconsistencies too may be 

 found here, but it is hoped that these are 

 within permissible limits of individual 

 opinion. 



The synonomies are not absolutely com- 

 plete in the sense that references to all 

 forms that have ever been described or 

 illustrated are included because triletean 

 forms are represented in too many pub- 

 lished illustrations for them all to be 

 cited. The chief concern has been to 

 give the references which include the type 

 material or throw light upon it. Other 

 references incidental to this purpose are 

 given in a good many instances, chiefly 

 to indicate the general features of occur- 

 rence, both stratigraphic and geographic. 



Stratigraphic distribution has been gen- 

 erally given for each. Such ranges are 

 always subject to revision for a number 

 of reasons. Many have been taken from 

 the stratigraphic distribution tables and 

 discussion pubhshed by Zerndt (1931, p. 

 169; 1937a, p. 68; 1937b, p. 590, 593; 

 1938; 1940, p. 142). The correlation chart 

 given by Gothan (1937, p. 299) has 

 been helpful in understanding the rel- 

 ative position of the mostly unfamiliar 

 named units of the Polish and Lower Sile- 

 sian stratigraphic succession. Approximate 

 equivalence of European and American 

 Carboniferous divisions are given in the 

 chart previously published by one of us 

 (Schopf, 1941, p. 9). Zerndt's data on 

 stratigraphic distribution is much more 

 extensive than information from any 

 other source and consequently deserves 

 most serious consideration. Doubtless 

 many forms not reported by him have a 

 greater stratigraphic range than has been 

 recognized. Zerndt's data, however, are 

 given for his spore ''types" rather than 

 for species. Most of his types and species 

 have general equivalence yet this is not 

 true in all cases and some discrepancy 

 may occur on this account. In general, 



