CH. XXVIIl] 



HABIT 



253 



reveal the family as one of the most interesting problems in Fern-mor- 

 phology, while in themselves they suggest antiquity and survival. The 

 attempt to place Loxsovia in relation to other Ferns has led to very divergent 

 results, which are summarised elsewhere {PJiil. Trans. Vol. 192, p. 47, 1899). 

 But its distinctiveness of character from other Ferns clearly indicates the 

 wisdom of Presl {Hymenophyllaceae, p. 98), and of Bommer {Bidl. Soc. Bot. 

 de France, Vol. 20, p. 35) in forming for it a separate Family of the Loxso- 

 maceae, in which the more recently discovered Loxsomopsis finds a natural 

 place. These Ferns take a position about the limit between the Simplices 

 and the Gradatae, and appear to be related to the Hymenophyllaceae and 



Fig. 521. Loxsoina CiinninghamiViX. ^, young 

 sorus with sporangia still protected by the 

 indusium [i, i). A, sorus rather older, with 

 sporangia (j, s) carried up on the elongated re- 

 ceptacle (/j), and showing sporangia (j-) inbasi- 

 petal sequence. B, base of receptacle in longi- 

 tudinal section showing a basipetal sequence cf 

 sporangia: C, D, mature sporangia, showing 

 the incompletely indurated annulus, and the 

 distal slit of dehiscence (x). [A and ^ x 20 ; 

 B X 250 ; C and D x 50.) 



Dicksonieae. Loxsonia was at one time definitely included in the Hymen- 

 ophyllaceae {^Synopsis Filicnui, 1874), but the new facts for Loxsomopsis 

 suggest that a separate position is preferable. 



Loxsonia is an elegant Fern with a stout rhizome bearing irregular roots, 

 and firm coriaceous, long-stalked leaves at intervals of about an inch. The\' 

 are 1-2 feet high, glabrous, 2 or 3 pinnate, and glaucous beneath, with open 

 venation. Loxsomopsis is a more stately Fern of Bracken-like habit, its slim 

 stiff fronds rising to a height of eight feet (Fig. 520): but its rhizome is 

 thinner than that oi Loxsonia. Both bear their sori terminal on the veins, mar- 

 ginal in origin, but deflected downwards in the course of development. The 



