41 



about 3 /i, thick, is slightly rugose between the 

 spines. 



Figured specimen. — Negative 4736; Trivoli 

 Cyclothem, maceration 1128-PI, slide 19, co- 

 ordinates, 143.6 X 41.9; size, 53.5 by 48.7 fi. 

 This species was also found in macerations 

 1128-1, 1128-J, and 1175-P, and in the Fith- 

 ian Cyclothem, maceration 1170-B. 



Genus Trivolites gen. nov. 

 Plate 7, figures 7-8 ; text figure 1 1 



Type species. — Trivolites laevigata sp. nov. 



Diagnosis. — The generic name Trivolites 

 is proposed for small spores having the fol- 

 lowing characteristics. The spores are radial, 



- : ^feip:-- ;; 



FIG. 11 — Trivolites laevigata sp. nov.; diagram- 

 matic reconstructions of holotype ; 36.9 by 

 35.6 v. 



A. View from proximal side. 



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



trilete, triangular in outline, and usually in 

 good proximal-distal orientation. The corners 

 are narrow and well rounded, and the inter- 

 radial sides are straight to slightly concave. 

 The trilete rays are distinct, have well de- 

 veloped lips on either side of the commissure, 



and extend almost to the spore margin. On 

 the proximal surface the area contagionis is 

 greatly thickened and extends at the radial 

 points beyond the distal margin of the spore 

 coat (text fig. 11). The outer margins of 

 the area contagionis are sharply delineated, 

 but the inner margins taper in thickness to- 

 ward the trilete rays. The surface of the spore 

 coat is levigate. The spore coat is 4 to 6 /x 

 thick. Known size range is 29.1 to 44.4 ju. 



Affinity. — Unknown. 



Derivation of name. — The name of the 

 genus refers to the Trivoli Cyclothem. 



Trivolites laevigata sp. nov. 

 Plate 7, figures 7-8; text figure 11 



Diagnosis. — The spores are radial, trilete, 

 triangular in outline, and usually in good 

 proximal-distal orientation. The narrow cor- 

 ners are well rounded, and the interradial 

 sides are straight to slightly concave. The 

 rays are distinct, between 18 and 22 /x long, 

 and extend almost to the ends of the radial 

 points. Lips are well developed, between 1 

 and 1.5 ju, wide on either side of the commis- 

 sure, and are slightly undulatory. The greatly 

 thickened, dense area contagionis projects at 

 the corners 3 to 4 /jl beyond the distal margin 

 of the spore coat. The outer margins of the 

 area contagionis are sharply delineated, but 

 the inner margin tapers in thickness toward 

 the trilete rays where the exine may be as 

 thick as other parts of the spore coat. The 

 surfaces of the spore coat are levigate, even 

 under oil immersion. The spore coat is from 

 4 to 6 fi thick. Dimensions ( 7 specimens) : 

 size range, 29.1 to 44.4 fx in maximum di- 

 ameter; median, 35.4 /i. 



Holotype. — Plate 7, figure 7; negative 5915; 

 Trivoli Cyclothem, maceration 1175-G, slide 

 17, coordinates, 130.3 X 51.9; size, 36.9 by 

 35.6 fji. 



Paratype. — Plate 7, figure 8; negative 6140; 

 Trivoli Cyclothem, maceration 1175-E, slide 

 4, coordinates, 138.4 X 33.6; size, 45.4 by 

 44.4 ii. 



Comparison. — The specimen illustrated by 

 Alpern (1959, pi. 13, fig. 371) probably be- 

 longs to this species but was not formally 

 named by Alpern. 



Derivation of name. — The species name re- 

 fers to the smooth (levigatus) surface. 



