Bd. III: 14) 
THE MESOZOIC FLORA. 
45 
Genus Thinnfeldia Ettingshausen. 
Thinnfeldia constricta n. sp. 
PI. 4, figs. 29 — 32, 34; text-fig. 10. 
A great number of specimens of TJiinnfeldia occur in the Hope Bay flora. They 
belong evidently to one species, which cannot be identified with any one described 
but is comparable with some few other Jurassic forms. In the following descrip- 
tion the specimens are regarded, according to the view now usually held, as pinnate 
fronds, not as branches with simple leaves, as in EttingSHAUSEN’s first diagnose. 
Fronds pinnate with a stout rachis, not or only slightly winged. Pinnules alter- 
nate, attached by a narrow base, not decurrent, narrowly lanceolate to broadly ovate, 
often rhomboidal, with narrow, obtu.se apex and tapering, cuneate base. Venation 
consisting of a distinct midrib reaching nearly to the apex, and strong, straight se- 
condary veins, which form an acute angle with the midrib and usually bifurcate 
once. 
A number of impressions of this species are shown in figs. 29 — 32 and 34, pi. 4; 
some other specimens, better preserved, are drawn in text-fig. 10. The fronds are 
very irregular in shape on account of the varying size and angle of attachment of 
