48 
angles to the midrib, simple or frequently forked either near the midrib or near the 
margin. 
Description of the Specimens. —Several fragments of fronds of this species are seen, 
natural size, on Plate VI, figs. 2, 3. On Plate IV, fig. 4, another leaf is shown, 
somewhat contracted towards the base, and with a stout midrib. This, perhaps 
more than any of the other examples, resembles the British specimens of Tceniopteris 
vittata. 
Remarks.— These specimens appear to me to be indistinguishable from those of 
T. vittata occurring in the Yorkshire Oolites. The form of the frond is perhaps a 
little more ribbon-shaped and less elongately elliptical than in the English fossils, 
though in the specimen shown on Plate IV, fig. 4, we have a type more attenuated 
at one extremity, like the British plants. I therefore do not attach any importance 
to such slight variations in the form of the frond. As regards the nervation, the New 
Zealand specimens appear to me to be identical with the British, in which, however, 
the nerves may be a little finer and closer. 
Occurrence. —Curio Bay, Waikawa (Middle Jurassic). 
Genus THINNFELDIA Ettingshausen, 1852. 
(Ahh. k.k. Geol. Reichs., Bd. i, Abth. 3, No. 3, p. 2.) 
Gothan(l) has recently proposed to remove three of the species from New Zealand 
here discussed to a new genus, Dicroidium, as distinct from Thinnfeldia. The fork¬ 
ing habit of the fronds of T. odontopteroides, T. lancifolia, and T. Feistmanteli is 
regarded as one point of dissimilarity, worthy of generic distinction. Others relate to 
certain features presented by cuticle preparations, especially the distribution of the 
stomata, and the presence or absence of subsidiary cells. As Antevs(2) has already 
pointed out, it is doubtful whether, as regards the latter points, there is any real 
distinction between these species and European members of the genus Thinnfeldia. So 
far as the branching of the frond is concerned, this feature does not appear to me of 
sufficient importance to warrant generic distinction, and I therefore prefer for the 
present to retain the well-established usage of referring the southern species to Thinn¬ 
feldia, to the members of which genus they are undoubtedly very similar in many 
respects. 
1. Thinnfeldia sp., cf. T. argentinica (Geinitz). Plate I, fig. 9. 
1876. Otopteris argentinica Geinitz, Palceontogr., Suppl. iii, Lief, ii, (2) p. 6, pi. ii, figs. 5a, 56. 
Diagnosis. —Frond pinnate or (?) dichotomizing ; pinnules thick, rhomboidal; nerves 
strong, arising independently from the rachis, and 'dichotomizing. 
Description of the Specimen. —-A fragment of a frond of Thinnfeldia, which is 
figured on Plate I, fig. 9, natural size, occurring in the New Zealand Geological Survey 
collection from the Clent Hills, shows several more or less rhomboidal pinnules, with 
strong dichotomizing nerves radiating from the base, and in most cases derived directly 
from the rachis. The pinnules appear to be somewhat thick and fleshy, and are 
contracted at the base. 
Remarks— The New Zealand specimen appears to agree fairly closely with Geinitz’s 
species from Argentina, the chief difference being that in the latter the pinnules are 
distinctly rhomboidal in shape, though less so in the New Zealand fossil, where the 
angles are more rounded. The nervation appears, however, to be very similar in both 
(1) Gothan (1912). 
(2) Antevs (1914). 
