105 
connate ; the lowest basal pinnules are semielliptic and inserted already on 
the rachis of the leaf, but still they are connected with the next leaflet of 
the pinna, so that it has to be considered as belonging to the pinna itself. 
The dichotomous fronds are either pinnatifid or pinnate-pinnatifid ; this 
depends on the state of development of the frond. In younger plants, when 
they are dichotomous, eacli branch represents a pinna, which is only pinnate, 
that is, it has only pinnules, which, however, also occur in the lower portion, 
below the point of division ; if they arc larger forms, each of the branches 
represents a chief rachis, which bear pinnae with pinnules, and which also 
continue below the point of division ; in these lower parts, however, the 
pinnae are shorter, while higher up they become much longer. The pinnules 
are of rather a varying form, sometimes obliquely ovate-oblong, sometimes 
quadrately ovate, entire or obliquely truncate above or indentate ; in the 
pinnate-pinnatifid frond the lowest basal pinnules arc also removed somewhat 
down the rachis, especially in the pinnae closest to the top. 
The venation is quite characteristic ; the greater portion of the veins, 
which altogether are not very numerous, originate, as it were, from a common 
point in the base of the leaflet by repeated furcation ; besides this, there are 
other veins coming out directly from the rachis of the pinna, which also arc 
repeatedly forked. The dichotomy of the leaf is pretty frequent ; it was 
observed by all the describers of this species, so it would follow that it is 
rather the rule than the exception. 
Locality and Horizon . — This species occurs at various localities on 
various horizons : — 
(«) In the Hawkesbury rocks, at Mt. Victoria, New South Wales 
(Plates XXIII, XXIV, XXV). 
(Jj) In the Wianamatta Shales at Clarke’s Hill, near Cobbitty, New 
South Wales (PI. XXVI, Pigs. 1, 2). 
( c ) In the Upper Mesozoic beds at Ipswich (Pl. XXIX, Pigs. 1, 2), 
and Tivoli Mines (Mr. Carruthers figures — compare our PI. 
XXVIII, Pig. 8), in Queensland; in the Jerusalem Basin, 
Tasmania (PI. XXIX, Pigs. 3, 4, 5). 
Although the above diagnosis was destined to comprise most of the 
varieties of this very variable form, yet some other forms have been described 
since. 
list 104— S9 p 
