XII COMPENDIUM. 



under side, the margin or the apex, rarely on both sides or on 

 the upper side. Spores isomorphous, producing independent 

 prothallia on which are developed both antheridia and archegonia. 

 Terrestrial or epiphytic, rarely aquatic. 



FAMILIES I X. (See my handbook on Malayan Ferns). 



GENERA 195. (Not treated with in this work). 



SUBORDER II. HYDROPTERIDES (Heterospore Fi 



licales, Water ferns). Leaves simple, or 2-lobed to 4-foliolate, 

 circinate or folded in the bud; sporophylla or their segments 

 metamorphosed into sessile or stalked, globose, ellipsoidal, pyriform 

 or bean-shaped sporocarps enclosing several to numerous sporangia 

 and placed on, or at the base of, the stipes of the barren leaves. 

 Spores heteromorphous, producing more or less rudimentary 

 prothallia, those of the macrospores bearing archegonia, those of 

 the microspores antheridia. Auquatic or subaquatic. 



FAMILY XI. MARSILEACEAE. Stems creeping in the mud. Leaves 

 without blade or with blades floating on the surface of the 

 water or rising above it, circinate in the bud. Sporocarps 

 bi- or plurilocular, each loculus containing both macrospores 

 and microspores. 



GENUS 96. MARSILEA. Normal leaves long-stalked, 

 4-foliolate; leaflets cruciate. 



FAMILY XII. SALVINIACEAE. Small plants floating on the water. 

 Leaves with a simple or deeply 2-lobed blade, folded in the 

 bud. Sporocarps unilocular, containing either macrospores 

 or microspores. 



GENUS 97. SALVINIA. Leaves simple, borne in 

 whorls of 3 of which 2 are floating, normal, 

 and the 3rd submerged, dissected into many 

 filiform segments, bearing the sporocarps on 

 the basal segment. 



