26 



x 8 



FIG. 6 — Latipulvinites kosankii sp. nov. ; diagram- 

 matic reconstructions of holotype; 40.5 by 

 35.0 ti. 



A. View from proximal side. 



B. Cross section through spore along X — X'. 



Latipulvinites kosankii sp. nov. 

 Plate 3, figures 13-14; text figure 6 



Diagnosis. — The spores are radial, trilete, 

 and triangular in outline. They are usually 

 in good proximal-distal orientation and have 

 well rounded corners and straight to slightly 

 concave or convex interradial sides. The dis- 

 tinct trilete rays are straight and extend to 

 the margin of the spore coat. Lips are poorly 

 developed, very narrow, and slightly elevated. 

 The elevated triradiate ridges, which are very 

 prominent, are thicker and darker toward 

 their sharply delineated outer margin (text 

 fig. 6). The ridges extend about halfway 

 to the interradial margin and at least two- 

 thirds of the distance to the corners opposite 

 the rays. The surface of the spore coat ap- 

 pears levigate under high dry objective, but 

 with careful focusing under oil immersion 

 objective minute puncta, which are largest 

 marginal to the rays, can be distinguished. 

 The spore coat is about 3 jx thick. Dimen- 



sions (8 specimens) : size range, 38.9 to 48.6 

 (jl; median, 41.5 \x. 



Holotype. — Plate 3, figure 13; negative 

 5962; Trivoli Cyclothem, maceration 1175- 

 C, slide 24, coordinates, 124.0 x 36.2; size, 

 40.5 by 35.0 p. 



Paratype. — Plate 3, figure 14; negative 

 5629; Henshaw Formation, maceration 1122- 

 G, slide 9 T, coordinates, 136.9 X 50.5; size, 

 44.4 by 37.3 /x. 



Comparison. — Latipulvinites kosankii ap- 

 pears somewhat similar to Ahrensis pontes 

 minutus Alpern, 1958, but the latter is smaller 

 (25 fi) . L. kosankii is also similar to the 

 specimen illustrated by Alpern (1959, fig. 

 159) and identified as A. cf. angulatus (Ko- 

 sanke) Potonie & Kremp, 1956. L. kosankii 

 strongly resembles a spore designated by 

 Neves (1958, pi. 2, fig. 6) as spore type "C", 

 except that the latter is more nearly circular 

 in outline and is larger (63 ll) . 



Derivation of name. — The species is named 

 in honor of Dr. Robert M. Kosanke, paleo- 

 botanist, U. S. Geological Survey. 



Genus Limitisporites (Leschik) 



Potonie, 1958 



Table 1 



Type species. — Limitisporites rectus Les- 

 chik, 1956. 



Affinity. — Probably gymnospermic. 



Genus Luegkisporites 



(Potonie & Klaus) Potonie, 1958 



Table 1 



Type species. — Lueckisporites virkkiae Po- 

 tonie & Klaus, 1954. 



Affinity. — Caytoniales? (Potonie and 

 Kremp, 1954, p. 177). 



Genus Lundbladispora Balme, 1963 

 Plate 3, figures 15-17 



Type species. — Lundbladispora willmotti 

 Balme, 1963. 



Comparison. — Lundbladispora willmotti 

 and L. simoni sp. nov. are markedly similar 

 to Crassispora except that Lundbladispora 

 has a better developed, continuous, thickened 

 equatorial zone, which accounts for its usual- 

 ly good proximal-distal orientation. Crassi- 



