On Spores in the Carboniferous Formation of Scotland. 109 



Size. — 2 mm. to 1*50 mm. 

 Horizon. — Millstone Grit. 

 Locality. — 23. 



Triletes VI. PI. III., Figs. 6a, 66, ^c. 



Macrospore very large. Triradiate ridge occupying one-half 

 of the upper surface. Area surrounding the three-armed star 

 finely punctate ; other portion of spore covered with numerous 

 conical spines. This is easily distinguished from the last by 

 its numerous stout spines and larger size. 



Size. — 2*3 mm. to 1*70 mm. 



Horizon. — Millstone Grit. 



Localities. — 23, 24. 



Triletes VII. PL III., Figs, la, 7i, and 7c. 



Macrospore similar in general character to Triletes VI., but 

 smaller. The small apiculi on the area of the triradiate ridge 

 are prominent ; the mamillate spines are about the same size 

 as those of the last form. 



Size. — 1'70 mm. 



Horizons. — Millstone Grit and Coal Measures. 



Localities.— 24:, 26, 34, 35, 36. 



Triletes VIII. PL III., Fig. 8. 



This is closely allied to Triletes VII., but the spines are 

 larger. 



Size. — 1*80 mm. 

 Horizon. — Coal Measures. 

 Locality. — 35. 



Triletes IX. PL III., Figs. 9a, %, 9c, U, 9e, 9/ 



Triradiate ridge extending over half of the upper surface ; 

 surrounding area ornamented with numerous small apiculi. 

 Other portions of spore covered with numerous short, thick 

 spines. Fig. 9c shows two of the spines in their natural 

 condition, and three that have been flattened by pressure. 

 Some specimens of this form have been found united in 

 groups of four. 



