SYNOPSIS OF THE GENERA. 
15 
unequal arcoles, sometimes reticulated only near tlie midrib or margin. Sori linear, continuous, or 
interrupted ; rnclusiiim narrow. 
37. Lonchitis, Zmw«MS. — ^ Ferns reticulated, producing unequal areoles. Sori oblong or linear- 
arcuate, produced on the apices of four or five convergent venules, which terminate in the sinus of 
tlie segments; indusmm linear. 
38. Pteris, iwmfeMS. — Veins forked; venules free, or their apices combined by a sporangiferous 
receptacle ; the inferior pair sometimes arcuately or transversely anastomosing, forming a single row 
of elongated costal areoles. Sori linear, continuous or interrupted, usually occupying the sides only 
of the segments ; indusium plane, linear, its base often sporangiferous. 
39. Onychium, Kaulfuss.-— Veins simple, direct, free, or combined at their apices by a transverse 
sporangiferous receptacle seated in the axis of the indusium. Sori short, linear, continuous, usually 
becoming confluent and covering the whole of the segment ; indusium plane, linear, slightly intra- 
marginal, the free margins of opposite indusia conniving over the midrib. 
Section II. Metasorece, J. Smith. — Sori intramarginal or costal. 
40. Lomaria, Wilklenoio. — Fronds dissimilar, the fertile contracted. Veins (sterile) forked, 
scarcely evident in the fertile fronds ; venules direct, free, with club-shaped apices usually terminating 
within the margin. Sori linear, elongate, continuous, arising from a thick elevated receptacle, often 
occupying nearly the whole disk ; indusium vaulted, revolute, and conniving, at length replicate and 
torn, seated on or within the m.argin. 
41. Blechnum, Linneeus . — Veins (sterile) forked ; venules direct, free, in the fertile fronds combined 
near the base at the point of forking by a transverse sporangiferous receptacle. Sori linear, con- 
tinuous or interrupted, costal, rarely medial ; indusium plane, conniving with the costa. 
42. Doodia, R. Brown . — Veins forked; venules arcuately anastomosing near the base, there gene- 
rally soriferous, then free and direct towards the margin. Soi-i oblong, straight or arcuate, trans- 
versely uniserial or biserial ; indusium plane. 
43. WooDWARDiA, Smith . — Veins reticulated, becoming free near the margin. Sori oblong or 
linear, elongated, uniserial, immersed, produced on the transverse costal venules ; indusium revolute, 
vaulted. 
Tribe IV. ASPLENIEjE, J. Smith. — Sori elongated oblique to the midrib or axis of venation borne 
on the superior or inferior sides, or on both sides, of the venules, and furnished with a special 
lateral plane or vaulted indusium. 
Section I. OrthopMehiecVj J. Smitli. — ^Veins all free. 
44. ScoLOPENDRiUM, Smith . — Veins forked; venules parallel, direct, free, with club-shaped apices, 
terminating within the margin. Sori linear, unilateral, produced on the proximate sides of the 
anterior and posterior branch of each fascicle of veins, and confluent in pairs (face to face) ; indusium 
(of each pair) with the free margins conniving, opening by a longitudinal suture. 
45. Diplazium, Swartz . — Veins forked, or pinnate; vemdes direct, free. Sori linear, produced on 
both sides of the venules (back to back), constituting binate sori; indusium plane. All, or the lower 
venules only, soriferous on both sides, the superior ones frequently producing simple sori, as in 
Asplenium. 
46. Asplenium, Lmneeus . — Vems forked or pinnate ; venules direct, free. Sori simpile, linear, 
oblong, or elongated, unilateral on the anterior side of the venules ; indusium plane or vaulted. 
Section II. Sympliophlehiem, J. Smith. — Veins anastomosing or reticulated. 
47. Ceterach, Willdenow. — FetMS forked or pinnate; venules more or less anastomosing, the lower 
anterior one soriferous on the side next the raches. Sori oblong or linear, unilateral, protruding 
through dense elongated scales ; indusium obsolete. 
