ANATOMY AND AFFINITY OF CERTAIN RARE AND PRIMITIVE FERNS. 389 
The spore-counts made are as follows : — 
Cheilanthes tenuifolia (Burm.), Sw. 32, 28, 27. 
tomentosa, Link. 32, 29. 
microphylla, L. 32, 30. 
hirta, Sw. 
vestita, Sw. 
Fendleri, Hk. 
graciUima, Eat. 
lanuginosa, Dav. 
32, 28. 
5A, 52, 48, 47. 
57, 53 
32, 30 
With the Pellseas examined the matter seems to stand on the same general 
footing recognised for Cheilanthes and N othochlaena. The annulus is almost 
vertical but does not reach the stalk. Irregularities in the annulus are uncommon. 
My spore-counts in P. falcata (R. Br.), F6e, are 54, 52 ; those of Marsh are 60, 56. 
In P. intramarginalis (Klf.), J. Sm., it is- 32 ; and 31, 30 have been noted by Marsh 
in P. andromedifolia (Klf.), F6e. Bilt in P. hastata (Thbg.), Prantl, it varies con- 
siderably. This is an expression of differences in spore-size, both large and small 
spores being present. The highest count made was 24, the lowest 16. 
But if the sporangial characters do not indicate a close affinity of Trismeria to 
Nothochlxna, Cheilanthes, and Pellxa, neither will they point a near relationship 
of Trismeria to Ceratopteris thalictroides (L.), Brong. The sporangia of Ceratopteris 
are large, and have a short, massive stalk (figs. 70, 71, 75). The stalk is always 
massive (fig. 74), and the annulus — though typically vertical and interrupted by the 
stalk — is very variable in construction. In some cases the stomium is well 
developed, and the annulus almost regular. In others no stomium is recognisable, 
or, though induration is well developed to the stalk on both sides, the stomium 
may be ill-defined. The spores are large and of a remarkable, and possibly archaic, 
type (figs. 72, 73). The spore-count in our material may be anything between 
24 and 12. 
General Conclusion. — The general conclusion drawn from this study of Trismeria 
is that the plant has no distinctive characters which justify its recognition as a 
distinct genus. It does not belong to the Cheilanthinse, but falls into line with the 
Gymnogramminse generally. It may well retain the position assigned to it by 
Sir Wm. Hooker as Gymnogramme ( Trismeria ) trifoliata, Desv., an “ Acrostichoid ” 
species of Ceropterid type. 
Text-fig. 30. 
