371 
Localities..— TASMANIA — Jerusalem, Whale’s Head. New 
SoutH Wates—Clark’s Hill, Hawkesbury Sandstones. QuEENS- 
LAND—Ipswich, Tivoli Mines. 
References.—Morris. Strezelecki’s Phys. Descrip. N.S. Wales 
and V.D. Land, 1845, p. 2, 49, t. 6, f. 2-4. M’Coy (Gleichenites) 
Annals Nat. Hist., 1847, XX., p. 147; Schimper, Traité dé Pal. 
Vég., 1869, I., p. 488 ; Feistmantel, Records Geol. Survey, India, 
1876, [X., pt. 4. pp. 123-124 ; Tenison-Woods, Proc. Lin. Soc., N.S. 
Wales, vol. VIII. pt. 1, pp. 106-107; R. Etheridge, junr., Cat. 
Aust. Fossils, 1878, p. 98. 
THINNFELDIA ODONTOPTEROIDES (Morris), 
Var. obtusifolia (Johnston). 
Frond bipinnate; pinne simple or dichotomous; rhachis 
strong and grooved, not winged; pinnules sub-opposite scarcely 
oblique, connate at the base, obtuse, broader than long, lower 
ones frequently emarginate ; upper margin emerging obliquely 
or at right angles to rhachis and roundly tapering downward 
towards lower margin, adhering base broadest ; lower pinnules 
free and relatively more square, emarginate, and shorter than 
the somewhat continuous or pinnatifid segments at the 
extremities of pinne ; the two inner pinnules at base of 
furcate pinne are slightly imbricate; pinne usually from 
three to five inches long, and from six to thirteen millimetres 
broad; veins extremely fine, all arising from the rhachis, 
dichotomous, diverging as they ascend. 
This fern is especially the characteristic form in 
certain shales at the foot of Spring Hill, From the 
extreme divergence of this form from the types figured 
originally by Professor Morris in Strezelecki’s work (Physical 
Descrip., N.S.W., and Tas.), and from the frequency which 
the very fine venules ascend from the rhachis independently, E 
was at first inclined to regard it as a distinct species allied 
to Odontopteris, but the further study of Dr. Feistmantel’s 
able investigations and of the fuller and more correct 
characters of the various forms given by him led me to 
abandon my original view, and refer the whole of the various 
forms at Spring Hill to Thinnfeldia odontopteroides. There is 
one beautifully preserved specimen, however, in my possession 
which from the delicacy -and independence of the branching 
venules would almost justify its inclusion under the 
genus Qdontopteris. This specimen particularly is almost 
identical in form with O. Schlotheimii, far more so, I 
believe, than the O. microphylla, M'Coy. The latter is 
found common in the fine sandstones of Clarke’s Hill, N.S. 
Wales (Wianamatta beds). The shales at Spring Hill appear 
to be older than the eruptive greenstone forming the high 
ridge at that place. It is possible that the shales at Spring Hill, 
may belong to a formation distinct from the Jerusalem basin. 
