J 



CYCADOFILICALES 27 



the species of Crossotheca are stamens of Cycadofilicales. Recently 

 Miss Benson has announced (83) the discovery of a new species of 

 Crossotheca (C. Grievii), which is described as the stamen of Heter- 

 angium Grievii. There are now recognized, therefore, nine sj)ecies, 

 and all of them have the general "epaulet" character described for 

 C. Hdninghausii. They differ only in such details as the form of 

 the sporangium-bearing blade (oval, cordate, or lobed), and in the 

 number and form of the sporangia. So similar are these species that 

 it seems safe to infer that they are all 

 stamens of Cycadofilicales. The foliage 

 of all of them is known, except that of 

 C. Hughesiana, and includes species 

 of Pecopteris (as P. exigua) as well as 

 of Sphenopteris (Lyginoiiendron). 



In 1887 KiDSTON (11) described 

 fronds of Neuropteris heterophylla 

 {Medullosa) in which both the pinnae , 

 and axis end in slender, naked, dichoto- 

 mously divided branchlets, each ulti- 

 mate division terminated by a four- ^ , 

 valved body. At the time these Fig. 2o.--Lrossoiiiaa Honing- 

 bodies were regarded simply as the ^'^"^"■- P^'-t'"'^ °f ^'■'"^'' ''''^^ ^'-^ 



,, . .^ . ,, r r o- 1 young stamens; X2.V — From 



"fructifications" of a fern. Since the photograph by Kidston (64) 

 seeds of this species have now been 



discovered, it is apparent that these bodies must represent its micro- 

 sporangiate structures. "Fructifications" of this kind, terminal 

 on naked, ultimate branchlets of a more or less modified frond, 

 with valves more or less united at base, have been referred to the 

 form genus Calymmatotheca. At least some of them are sporangia 

 more or less united below and free above, and in some cases the 

 dehiscence (internal) and the spores have been found. Of course 

 such a structure is a synangium,' but its terminal relation to 

 ultimate branches of the frond is quite different from that of the 

 synangia of existing Marattiaceae. There is danger of confusng 

 these structures with the cupule-likc investment of such seeds as 



I This term is used with no implication of an opinion as to the nature of 

 the structure. 



