16. HTMENOPHYLLUM. , 57 



down, furnished only with a central casta ani a few faint irregular free spurious 

 venules, the margin not thickened ; sort solitary, terminal, the cuneate base 

 sunk in the frond, divided about halfway down ; valves rounded, entire. — Baker, 

 in Linn. Proceed. 9. p. 340. tab. 8. Jiff. E. Trichomaues microphyllum, Kulin. 



Hab. Moulmein, Rev. C. S. Parish. — The smallest and simplest species of the genus, 

 rivalling in minuteness Trichomarus Barklianum and viliense. 



3. H. marginatum, Hk. & Gr. ; st. 2-4 lin. 1. ; fr. linear, once or twice forked, 

 about 1 in. 1., 1 lin. br., furnished with a central casta ; texture firm ; margin 

 bounded by a thickened line, the apex emarginate ; sari terminal, solitary, sub- 

 orbicnlar, divided down nearly to the base, with convex entire cafoas. — Hk. & Gr. 

 Ic. Fil. t. 34. Hk. Sp. 1. p. 87. Pachyloma, V. D. B. 



Hab. Port Jackson, Anstralia, rare. — Substance of the &ond undulated. 



4. H. a;,j)lenioiJes, Sw. ; St. 1-2 in. 1., slender ; fr, 2-4 in. 1., by i-1 in. br., 

 pendulous, oblong in general outline, pinnatifid to within a short distance of 

 the rachis ; hwer lobes rhomboidal-cuneate, cleft on both sides or one only; 

 upper lobes simple, linear-oblong ; sari 1-4, terminal on the segments of the 

 lobes ; invol. orbicular, free, cleft nearly to the base. — Hk. Sp. 1. p. 87. Ic. 

 PI. t. 957. 



Hab. Tropical Americs, from Cuba and Mexico southward to Brazil. — Easily recog- 

 nizable by it^ peculiar habit of growth. 



** Fronds glabrous, one to four times pinnatifid. — Sp. G-30. 



5. H. abruptum, Hk. ; St. about J in. 1., very slender ; fr. ^1 in. 1., J-J in. br., 

 oblong, pinnatifid to within a short distance of the main rachis ; pinna! linear, 

 erecto-patent, about J in. 1., 1 lin. br., sometimes dichotomously forked, only a 

 central midrib in each division ; sori 1 or 2 to a frond, terminal on the apex or 

 upper segments ; invol. not divided more than halfway down, the base cuneate, 

 the valves rounded ; recept. occasionally protruded. — Hk. Sp. 1. p. 88. t. 31. B. 

 H. brevifrous, Kunze. 



Hab. Jamaica, Cuba, Grnatemala, Venezuela, and Brazil. — Allied to M. rairum, but 

 the main rachis has a broader wing below, and the pinnae are at most simply forked. 



6. H. mnioides. Baker; st. not more than \ in. 1., very slender ; fr. 1-2 in. 1., 

 J in. br., linear, once pinnatifid; rachis winged, throughout ; the segm. all 

 quite simple, linear, the lower ones slightly imbricated, erecto-patent, 2 lin. 1., 

 J lin. br, the upper ones pressed close to the rachis and much imbricated ; sori 

 solitary on three or four of the upper segments, large compared with the size of 

 the plant, divided about halfway down, the base campanulate ; valves more than 

 half a circle, large, membranaceous. 



Hab. New Caledonia, Pic du Mont Mu, DepJanche. — A minute moss-like plant, with 

 the habit of Mnium wndulatum or serratum, but dark-brown in colonr. It is allied to 

 the preceding and the following, but whilst the segments are quite simple, the main 

 rachis is scarcely winged below. 



7. H. teneUum, Kuhn ; rhizome wide-creeping ; St. 1 in. or less 1., slender, 

 naked ; fr. 1-2 in. 1., J-1 in. br., oblong- deltoid, tripinnatifid ; main rachis winged 

 dojrn to the base ; pmnm 4-6-jugate, deltoid, cuneate-truncate at the base on the 

 lower side ; lower pinnl. 1-2, cleft at tip with ligulate blunt Jobes \ lin. br. ; swi 

 2-6 to a pinna, terminal in the lobes ; surfaces naked ; inv. with hemispherical 

 lobes and a cuneate entire immersed base. — H. emersum, Baker, Syn. Fil. edit. 1. 

 p. 457. Adiantum tenellum, Jacq. Coll. t. 21. fig. 3. 



Hab. Ceylon and Mascaren Isles. — Has nothing to do with H. leneUwn, D, Don, 



H 



