52 
of the segments. The lamina is dissected up to the central midrib or rachis into 
truncate segments of unequal breadth, traversed by several parallel veins both simple 
and forked ; the lamina is continuous over the rachis of the frond, and the segments 
are not- laterally attached as in Pterophyllum 
Description of the Specimens. —A few fragments of a species of Nilssonia occur 
at Mokoia, Gore, three of which are figured on Plate VIII, figs. 2, 3, and 9, all 
natural size. That shown by fig. 3 measures nearly 4 cm. in length, and has a 
breadth of about 1 cm. The upper segment is not apical. The appearance of the 
frond here is due to the segments on either side of the midrib being imperfectly 
preserved. The segments are of unequal breadth, and truncated distally. The nerva¬ 
tion is only faintly preserved, but most of the lateral nerves appear to be simple 
(cf. fig. 9). A short fragment similar to the last, showing the nerves more clearly, 
is shown by fig. 9 of the same plate. The unequal breadth of the segments is 
clearly seen here. A similar specimen is also seen in fig. 2. 
Remarks. —It seems to me very probable that these specimens are simply small 
fronds of Nilssonia compta (Phill.), similar to those figured by Oldham and Morris(l) 
and by Seward(2). 
Occurrence. —Mokoia, Gore (? Lower Jurassic). 
2. Nilssonia elegans sp. nov. Plate VIII, fig. 8 ; Plate IX, figs. 1, 3. 
Diagnosis. —Leaf up to 9-10 cm. in length, and from 2 mm. to 10 mm. broad ; 
midrib strong, L5 mm. across ; lamina very narrow, entire or lobed or divided to the 
midrib ; lobes of unequal size, more or less rectangular; apex subacute or bluntly pointed. 
Description of Specimens. —-An undivided frond, about 9 cm. long, but only 7 mm. 
across at its broadest part, is seen on Plate_ IX, fig. 1, natural size. It apparently 
has an acute apex. The nervation is not seen in this specimen. Another incomplete 
specimen, 5 cm. long, with a more or less deeply lobed lamina, is shown twice enlarged 
on Plate IX, fig. 3. The nerves are here faintly seen. They are fine, parallel, and 
somewhat distant, and no doubt occasionally fork. The narrower leaves, which are 
seen scattered about on the same specimen, appear to be either young fronds of this 
species in which the lamina is very narrow, or the long basal portions of leaves. 
A drawing of a group of three leaves is shown on Plate VIII, fig. 8. These are 
similar to those just described. The lobes or divisions are very irregular in size, 
and are truncated distally. Here again the nervation is only very faintly preserved. 
Remarks. —This plant has something in common, as regards habit, with Nilssonia 
polymorpha Schenk(3), a much larger plant, quite distinct specifically, but showing 
equally transitions from the simple to a compound leaf. It does not agree with 
any of the species recently figured by Nathorst(4). 
Type. —-New Zealand Geological Survey collection. 
Occurrence. —Mataura Falls, Southland (Middle Jurassic). 
Genus PTEROPHYLLUM Brongniart, 1824. 
(Ann. Sci. Nat., ser. i, vol. iv, p. 211.) 
Pterophyllum matauriensis Hector. Plate IX, fig. 2 ; Plate XII, fig. 1. 
1886. Pterophyllum matauriensis Hector, Det. Cat. & Guide, N. Zeal. Court, Ind. & Col. 
Exhib., p. 66, text-fig. 30a(7). 
Diagnosis. —Pinnate fronds, up to 11 cm. in length. Rachis stout, up to 2-5 mm. 
across, grooved ; pinnae attached at the side of the rachis ; alternate, or more rarely 
subopposite, 2-5 cm. to 3 cm. in length, broadest near the point of attachment, up 
(1) Oldham and Morris (1863), pi. xii, figs. 2-5. (3) Schenk. (1867), p. 127, pi. xxix ; pi. xxx, 
(2) Seward (1900), text-fig. 39 on p. 225. figs. 1-5 ; pi. xxxi, figs, la, 16, lc. 
(4) Nathorst (1909). 
