_Marattia_. This genus, which extends “all round the world within the tropics[753],” includes some species which closely resemble _Angiopteris_, while others are characterised by more finely divided leaves with smaller ultimate segments. The fleshy stipules occasionally have an irregularly pinnatifid form (fig. 241, B). The sporangia are represented by oval synangia[754] (fig. 245, A; the black patches at the ends of the lateral veins) composed of two valves, which on ripening come apart and expose two rows of pores formed by the apical dehiscence of the sporangial compartments (fig. 245, A′, B). In _Marattia Kaulfussii_ the sori are attached to the lamina by a short stalk (fig. 245, B, B′) and the leaf bears a close resemblance to those of the Umbelliferous genera _Anthriscus_ and _Chaerophyllum_. The vascular system is constructed on the same plan as that of _Angiopteris_ but is of simpler form. [Illustration: FIG. 245. A. _Marattia fraxinea_. A′. A single synangium showing the two valves and pores of the sporangial compartments. B, B′. _M. Kaulfussii_. C. _Kaulfussia_ (synangium showing pores of sporangial compartments). D, E. _Marattiopsis Münsteri_. (C, after Hooker; D, E, after Schimper.)] _Danaea._ Danaea, represented by about 14 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[755] agrees in general plan with that characteristic of the family. _Kaulfussia._ The form of the leaf (Vol. I. p. 97, fig. 22) closely resembles that of the Horse Chestnut; the stem is a creeping dorsiventral rhizome with a vascular system in the form of a “much perforated solenostele[756].” 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)[757]. Copeland has recently described a Marattiaceous leaf which he makes the type of a new genus, _Macroglossum alidae_. The sori are nearer the margin than in _Angiopteris_ and are said to consist of a greater number of sporangia. The photograph[758] of a single pinna which accompanies the brief description hardly affords 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.)