GENUS SPENCERISPORITES 



55 



nated as Spencerites. Similar but isolated 

 spores were described by Kubart (1910) as 

 S. membranaceus, an incorrect generic des- 

 ignation according to the present Inter- 

 national Code of Botanical Nomenclature. 



Ibrahim (1932) described spores which 

 he designated as Sporonites radiatus, later 

 designated as Zonales-sporites radiatus Ibra- 

 him by Ibrahim (1933) and by Loose 

 (1934)! Zerndt in 1934 described similar 

 spores as Triletes karczewskii. 



The spores of the two species are appar- 

 ently identical. Horst (1955, p. 193) stated 

 that Zerndt himself was of this opinion. 

 Dijkstra (1955a, p. 343) stated, "As there 

 exists no doubt that Microsporites kar- 

 czewskii and Triletes radiatus (Ibrahim) 

 Schopf, Wilson, and Bentall are identical, 

 the name karczewskii must be changed into 

 radiatus." 



Later Zerndt (1937b) described spores 

 somewhat similar to, but distinguishable 

 from, those of Ibrahim's Sporonites radia- 

 tus from the Westphalian E of Bohemia 

 and designated them as Triletes gracilis. 

 Schopf, Wilson, and Bentall (1944) recog- 

 nized three species which they felt were 

 referable to three separate genera: T. radi- 

 atus (Ibrahim) Schopf, Wilson, and Ben- 

 tall, Endosporites? karczewskii (Zerndt) 

 Schopf, Wilson, and Bentall, and Cirratri- 

 raditesf gracilis (Zerndt) Schopf, Wilson, 

 and Bentall. 



Dijkstra (1946) recognized two species of 

 Microsporites, used as a generic term but 

 not diagnosed as such: M. karczewskii 

 (Zerndt) Dijkstra, and M . gracilis (Zerndt) 

 Dijkstra. The author himself (Dijkstra, 

 1955a) later rejected the name Micro- 

 sporites in favor of a questionable referral 

 to Endosporites [E.f radiatus (Ibrahim) 

 Dijkstra] as Schopf, Wilson, and Bentall 

 (1944) had done previously in E.f kar- 

 czewskii. 



Because the author (Dijkstra, 1955a, 

 1957) has rejected Microsporites, it cannot 

 be considered a valid generic designation 

 (International Code, Article 33, see Lan- 

 jouw) , although Potonie and Kremp 

 (1954, 1956) and Horst (1955) consider it 

 as such. In 1951 Chaloner fully described 

 the spores of Spencerites insignis Scott, and 



similar but isolated spores which Chaloner 

 referred to Spencerisporites karczewskii 

 (Zerndt) Chaloner. Potonie and Kremp 

 (1954, 1956) rejected this generic name on 

 the basis of the priority of Microsporites 

 Dijkstra (which Dijkstra has rejected, as 

 noted above) and stated that although nei- 

 ther Dijkstra (1946) nor Chaloner (1951) 

 presented generic diagnoses, their intent 

 was the same and was clear from their spe- 

 cific descriptions. Unlike Dijkstra, Chalo- 

 ner (1951, p. 861-862) did present a clearly 

 indicated generic diagnosis. Dijkstra 

 (1955a, p. 343) rejected the name Spenceri- 

 sporites on the basis of recommendations 

 made at the 1951 Heerlen Congress. These 

 recommendations have no standing as re- 

 gards the International Code of Botanical 

 Nomenclature and cannot be considered as 

 a basis for rejecting the name Spencerispo- 

 rites. 



Because, in my opinion, these spores are 

 not closely related to Triletes, Endospor- 

 ites, or Cirratriradites, because all certainly 

 should be referred to the same genus, and 

 in view of the above comments, it seems 

 that Spencerisporites Chaloner is the only 

 correct generic designation. Chaloner (1951, 

 p. 862) designated Zerndt's (1934, pi. 

 XXXI, fig. 3) specimen as the holotype of 

 S. karczewskii which in turn is the type of 

 Spencerisporites. Although Zerndt's speci- 

 men can be regarded as the holotype, his 

 specific epithet is a later synonym of Ibra- 

 him's in Sporonites radiatus, so that the 

 holotype is correctly referred to Spenceri- 

 sporites radiatus (Ibrahim) n. comb. 



Potonie and Kremp (1956) recognized 

 four species which are: Microsporites gra- 

 cilis (Zerndt) Dijkstra, M. karczewskii 

 (Zerndt) Dijkstra, M. (Spencerites) mem- 

 branaceus (Kubart) n. comb., M. radiatus 

 (Ibrahim) Dijkstra (Potonie and Kremp 

 [1956], not Dijkstra, are responsible for this 

 combination) . I have been able to recog- 

 nize only two distinct forms of spores of 

 Spencerisporites from Illinois coals. These 

 are referred to 5. cf. S. radiatus (Ibrahim) 

 n. comb, and S. cf. S. gracilis (Zerndt) n. 

 comb. Detailed descriptions of these spores 

 are given in an effort to shed some light on 



