56 Bowei'.—Studies in the Phytogeny of the Filicales. VII. 
it is hidden by the sporangia when mature: but it is seen in Fig. 41, a. 
Thus the position and investment of the sorus are not distinctive from that 
seen among the Dicksonioid derivatives. But the stem and the petioles of 
this Fern are covered by chaffy scales resembling those of Nephrodium , 
while the Dicksonioids have hairs. The vascular system of the upright 
stock of Acrophorus is a dictyostele, and the leaf-trace is highly divided, as in 
Nephrodium. These features support the position of Acrophorus among the 
Aspidiinae assigned to it, together with Cystopteris, by Prantl. 1 Notwith¬ 
standing such soral similarities as they may present to Hypolepis and other 
Dicksonioid derivatives, these genera are to be ranked as of Nephrodioid 
affinity. 2 
I am indebted for material of Acrophorus to the Director of the Calcutta 
Garden, through Mr. Cave of Darjeeling. 
Monachosorum , Kze. 
Another parallel but distinct case is the Fern first described byKunze 
as Monachosorum davallioides , and now named M. subdigitatum (Bl.), Kuhn. 
It has been ranked by various authors as Aspidium , Polypodium, Gymno- 
gramme , Phegopteris , Anogramme , and Desmopodium. This shows the 
uncertainty there has been as to its position. Finally, it is retained as the 
single species of the genus as originally named. 
Kuhn 3 ranked this genus as a special division (C) of his Gymno- 
grammeae. He relates how Kunze placed it close to Polypodium\ Fde 
ranked it doubtfully with Anogramme ; Moore, as a doubtful genus before 
Polypodium , from which genus it is sharply distinguished by habit. This would 
relate it best with Leucostegia, asBeddome has placed it. Finally, Kuhn retains 
it, partly on ground of habit, partly of its simple hairs, and partly of the absence 
of swelling of the nerve-endings, as a substantive genus ; Christ ranks it with 
Gymnogramme (l.c., p. 76) ; Diels 4 places it as a substantive genus next to 
Dennstaedtia , with the remark that its habit recalls Davallia , but that the 
views of authors diverge as to its systematic position. It will be seen that 
the relation to Dennstaedtia is probably the nearest. 
Material, both dried and wet, of Monachosorum was obtained for me by 
Mr. Cave from Darjeeling, through the kindness of the Director of the 
Calcutta Garden. It showed the external characters already described for the 
species, and in addition one which, though noted by Sir Wm. Hooker, seems 
to have passed out of sight, viz. the existence of bulbils in the axils of the 
primary pinnae of certain specimens. 5 The fact that these are present in 
Monachosorum provides a useful point of comparison with Dennstaedtia ; 
1 1. c., p. 16. 
2 Compare Studies, IT, Ann. of Bot., vol. xxvi, pp. 302-5, and especially C. Christensen, 
A Monograph of the Genus Dryopteris , 1913, p. 64. 
3 Die Gruppe der Chaetopterides, 1882, p. 344. 
4 E. and P., i. 4, p. 218. 5 See Sp. Fil., vol. iv, p. 256. 
