EQUISETACE.E FILICES. 
381 
8. E. Mackaii (Newra.) ; st. simple or very slightly branched 
very rough with 8 — 12 furrows, sheaths close ultimately wholly 
black, teeth slender persistent. — E. elongatum Hook, not Willd. 
— St. 1 — 3 feet high, simple or with solitary distant branches. 
Catkins with an apiculus. Sheaths quite cylindrical, pale green 
with a black band beneath the teeth but ultimately wholly black. 
Teeth much more persistent than in the preceding, usually black. 
— Mr. Newman has shown (Phyt. i. 306.) that this is not the 
E. elongatum (Willd.) which is the same as E. ramosissimum 
(Desf.), and named it " after its original discoverer Mr. J. T. 
Mackay." Mountain glens. P. VII. VIII. 
9. E. variegatum (Schleich.) ; st. simple or very slightly 
branched very rough with 5 — 9 furrows, sheat/is slightly enlarged 
upwards green below black above, teeth obtuse each tipped with a 
deciduous bristle. — E.B. 1987. — St. about a foot long, erect or 
decumbent, usually' simple except at the base. Lower half of 
the sheaths green like the stem, upper part black ; teeth per- 
sistent, black in the centre, with a white membranous margin. 
Catkin apiculate. — Sands near the sea or in wet places in moun- 
tain valleys. P. VII. VIII. 
See Mr. Newman's valuable observations on the species of this 
genus in the Phyt. Nos. 15, 16, 17, 23, and the Rev. J. B. Bri- 
chan's excellent paper in No. 18. of the same Journal. It seems 
highly probable that a different arrangement of the genus will be 
the result of a more careful study of the living plants, as, to my 
mind, the present specific distinctions are far from being satis- 
factory. 
Order XCIII. FILICES. 
Leafy plants with a rhizoma or trunk. L. or fronds with a 
circinate vernation (Tribe VIII. excepted), simple or divided. 
Fructification springing from the veins on the under side or at 
the edge of the 1. and consisting of 1 -celled thecal stalked and 
with an elastic ring or sessile and without a ring. 
* Thecm with an elastic marginal ring. 
Suborder I. POLYPODIACE^. 
Theca? opening transversely ; ring vertical, usually incom- 
plete. 
Tribe I. POLYPOBIEJE. Sori nearly circular, without an 
indusium. 
1 . Allosorus. Sori circular, at length confluent, concealed by 
the reflexed margin of the frond. 
