XX] OPHIOGLOSSALES 321 



resemblance to those of the Umbelliferous genera Anthriscus and Chaero- 

 phyllum. The vascular system is constructed on the same plan as that of 

 Angiopferis but is of simpler form. 



Banaea. Danaea, represented by about ] 4 species confined to tropical 

 America, is characterised by simple or simply pinnate leaves with linear 

 segments bearing elongated sori extending from the midrib almost to the 

 margin of the lamina. Each sorus consists of numerous sporangia in two 

 parallel rows united into an oblong mass partially overarched by an 

 indusium (fig. 242, E, i) which grows up from the leaf between the sori. 

 In the portion of a fertile segment shown in fig. 242, E, the apical pores 

 are seen at a ; and at b, where the roof of the synangium has been removed, 

 the spore-bearing compartments are exposed. The vascular system' agrees 

 in general plan with that characteristic of the family. 



Kaulfvssia. The form of the leaf (Vol. I. p. 97, fig. 22) closely re- 

 sembles that of the Horse Chestnut ; the stem is a creeping dorsiventral 

 rhizome with a vascular system in the form of a ""much perforated 

 solenostele^." The synangia are circular, with a median depression; 

 each sporangial compartment opens by an apical pore on the sloping sides 

 of the synangial cup (fig. 245, C)*. 



Copeland has recently described a Marattiaceous leaf which he makes 

 the type of a new genus, Maoroglossum alidae. The sori are nearer the 

 margin than in Angiopteris and are said to consist of a greater number of 

 sporangia. The photograph^ of a single pinna which accompanies the 

 brief description hardly afibrds satisfactory evidence in support of the 

 creation of a new genus. The structure of a petiole which I have had 

 an opportunity of examining, through the kindness of Mr Hewitt of 

 Sarawak, shows no distinctive features. 



III. Ophioglossales. (Isosporous and Eusporangiate.) 



The three genera, Ophioglossum, Botrychium, and Hehnintho- 

 stachys, are characterised by the division of the leaves 'into a 

 sterile and a fertile lobe. The fertile lobe in Ophioglossum 

 bears two rows of spherical sporangia sunk in its tissue ; in 

 Botrychium and Helminthostachys the spores are contained in 

 large sporangia with a stout walP. The prothallus is sub- 

 terranean and without chlorophyll. In the British species of 

 OpMoglossvm, 0. vulgatum (the adder's tongue fern), an almost 

 cosmopolitan species, the sterile part of the frond is of oval 

 form and has reticulate venation. In 0. pendulum and 0. 



1 Brebner (02) ; Eudolph (05). = Tansley (08) p. 90 ; Kiihn (90). 



3 Pelourde (08) has recently dealt with the anatomy of recent and fossil 

 Marattiaceous ferns. 



1 Copeland (08) PI. i. (09) PI. v. » Bower (96). 



