36 



PALEOZOIC FOSSIL SPORES 



Nomina excludende 



1. Reticulati-sporites angulatus Ibrahim, 1933, Spo- 

 renformen des Aegirhorizonts, etc., p. 35, pi. 7, 

 fig. 59. 



2. Reticulata-sporites bireticulatus (Ibrahim) Loose, 

 1934, Inst. Palaobot. Arb., vol. 4, no. 3, p. 158, 

 pi. 7. fig. 28. 



Sporonites bireticulatus Ibrahim, 1932, Neues 

 Jahrb.. Beilage-Band 61, Abt. B. p. 447, pi. 14, 

 fig. 1. 



Reticulati-sporites bireticulatus (Ibrahim) Ibra- 

 him, 1933, Sporenformen des Aegirhorizonts, etc., 

 p. 35, pi. 1. fig. 1. 



3. Reticulati-sporites facierugosus Loose, 1934, Inst. 

 Palaobot. Arb., vol. 4, no. 3, p. 155, pi. 7, fig. 26. 



4. Reticulata-sporites mediapudens Loose, 1934, idem, 

 p. 158, pi. 7. fig. 8. 



5. RbTICULATI - SPORITES MICRORETICULATUS (Loose) 



Loose, 1934. idem, p. 155. 



Sporonites microreticulatus Loose, 1932, Neues 

 Jahrb.. Beilage-Band 67, Abt. B, p. 450, fig. 37. 



6. Reticulati-sporites morosus Loose, 1934, Inst. 

 Palaobot. Arb., vol. 4, no. 3, p. 154, pi. 7, fig. 2. 



7. Reticulati-sporites nexus (Loose), Ibrahim, 1933, 

 Sporenformen des Aegirhorizonts, etc., p. 34. 



Sporonites nexus Loose, 1932, Neues Jahrb., 

 Beilage-Band 67, Abt. B, p. 450, fig. 35. 



Reticulati-sporites nexus (Loose) Ibrahim, Loose, 

 1934. Inst. Palaobot. Arb., vol. 4, no. 3, p. 156, 

 pi. 18, fig. 35. 



8. Reticulati-sporites sifati Ibrahim, 1933, Sporen- 

 formen des Aegirhorizonts, etc., p. 35, pi. 8, fig. 67, 



9. Reticulata-sporites spongiosus Ibrahim, 1933. 

 idem, p. 39, pi. 8, fig. 71. 



10. Reticulati-sporites vinculatus (Ibrahim). Loose, 

 1934, Inst. Palaobot. Arb.. vol. 4, no. 3, p. 156. 



Sporonites vinculatus Ibraham, 1932, Neues 

 Jahrb., Beilage-Band 67, Abt. B, p. 448. pi. 15. 

 fig- 19. 



Reticulata-sporites vinculatus (Ibrahim) Ibrahim, 

 1933, Sporenformen des Aegirhorizonts, etc., p. 39, 

 pi. 2, fig. 19. 



Genus Laevigato-sporites (Ibrahim, 

 1933) emend., S. W. and B. 



Plate 1, figures 5-5b 



Symmetry. — Spores bilateral, mono- 

 lete. 



Shape. — Originally broadly bean- 

 shaped ; elongate oval in the plane of lon- 

 gitudinal symmetry, round or oval in the 

 transverse plane. When compressed the 

 spores tend to be folded variously depend- 

 ing on the size and morphology of the 

 various specific types of spores. 



Size. — Spores of various species range 

 from about 20 to over 130 microns in 

 their long dimension. 



Ornamentation. — Smooth to finely punc- 

 tate, apiculate or rugose ; rarely showing 

 pronounced reticulation or strong apicu- 

 lae. 



Haptotypic structures. — Consisting of 

 a simple monolete linear suture, generally 

 without lips specially distinguished, and 

 usually continued for more than half the 

 total length of the spore. The suture may 

 be very inconspicuous if it coincides in 

 position with the edge of a compressed 

 spore, or with the axis of a longitudinal 

 fold. Ends of very delicate arcuate ridges 



are sometimes distinguishable flaring lat- 

 erally from both ends of the suture line. 



Spore coat. — Varying somewhat in 

 thickness relative to the other dimen- 

 sions; the spore coat is oftentimes thin 

 and translucent. The internal cavity is 

 sometimes more *'bean-shaped" than the 

 external outline due to internal thickening 

 of the spore coat in the central proximal 

 region. 



Affinity. — Smaller species of Laeviga- 

 to-sporites agree with some forms ob- 

 tained from filicinean type fructifications. 

 There is now no particularly good evi- 

 dence as to the affinity of the larger forms. 

 Fredda Reed (1938, p. 333) has obtained 

 spores of this type from an extraordinary 

 new type of Calamarian fructification 

 which are approximately 50 microns in 

 length. Spores of Zeilleria are of this 

 type (Florin, 1937, p. 316-7) but it is not 

 now possible to decide whether that genus 

 belongs to the ferns or pteridosperms 

 (Halle, 1933, p. 88). The "distal fur- 

 row" of Zeilleria spores remarked by 

 Florin (1937, p. 317) appears no more 

 definite than many of the fortuitous folds 

 seen in spores of Laevigato-sporites. 



It thus appears that species of Laevi- 

 gato-sporites could conceivably pertain to 

 at least three distinct contemporaneous 

 orders of Paleozoic plants. It seems 

 doubtful that our information on these re- 

 lationships will be greatly improved in 

 the immediate future and until it is pos- 

 sible to revise the genus on the basis of 

 reliable evidence it will serve a useful 

 geological, if not a botanical, purpose. In 

 a good many instances species of Laevi- 

 gato-sporites form a majority of the 

 spores obtained from certain coal beds. 

 They are, however, rare or absent in a 

 number of lower Pottsville coals that have 

 been examined. 



Spores evidently belonging to Laevi- 

 gato-sporites have been assigned to types 

 B,a, B,b, and Bg by Raistrick (1933, 

 1937) (Knox, 1938). Millott's types 6 

 and E^a (Millott 1939) and Knox' (1942) 

 Type 6K may also belong here. 



Remarks. — Nine species, one of which 

 includes three designated formae, are now 

 listed for Laevigato-sporites. Ibrahim 

 originally assigned two species to the 

 genus. The second of these, L. ellipsoides, 

 is now referred to Monoletes. It is pos- 



