Geology and paleontology / by B.K. Emerson [and others].

Date:
[1910]
Catalogue details

Licence: In copyright

Credit: Geology and paleontology / by B.K. Emerson [and others]. Source: Wellcome Collection.

    251/318 (page 153)
    whence they are rather abruptly rounded to the obtuse apex ; margin obscurely but relatively finely serrate except in the basal portion ; mid- rib very thick, straight; secondaries numerous, about 18 pairs, very strong, alternate, at somewhat irregular distances, arising at an angle of about 450, slightly curving upward, usually with several craspedo- drome branches near the margin, campto-craspedodrome; the secon- daries usually arching just at the margin and joining the one next above with small nervilles, numerous, very prominent and deeply marked, mainly once broken though often percurrent and at right angles to the secondaries. Lateral leaflets of various sizes but in general much smaller than the terminal, elliptical-oblong in outline, abruptly rounded and very unequal-sided at base, moderately acuminate at apex ; margin and nervation practically the same as in the terminal leaflets. This fine species is represented by a dozen or more examples, several of which are nearly perfect. The terminal leaflets are from 13 to about 23 cm. long and from 7 to 12 cm. wide, while the lateral leaflets are from about 8 to probably 15 cm. long and from 3.5 to 8.5 cm. wide. These leaflets are mainly detached, but occasionally two or more are found closely associated and overlapping, and in one instance matted together in such a way as to suggest the probability of former union. There are also preserved in association with them objects that look very much like the rachis of a large compound leaf, but there is no actual evidence to show that these leaflets were ever borne on them. This species would seem to find its nearest relative in Hicoria ( Carya) antiquora (Newb.) Kn.1 That species also has large, cori- aceous leaflets, but they differ in shape and in the configuration of the margin, being regularly finely serrate. The nervation is of much the same type. Family BETULACEjE Betula (branch), pi. xxiv, fig. 2. The collection contains a single fragment of a branch showing the lenticels characteristic of this genus. The branch was about 1 cm. in diameter. Corylus macquarrii (Forbes) Heer. Corylus macquarrii (Forbes) Heer, Urwelt d. Schweiz, p. 321, 1865. The collection contains a large number of leaves that belong to this well-marked species. 1 Cf. Lesquereux, Tert. FI., p. 289, pi. lvii, figs. 1-5, 1878; Newberry, Later Extinct Floras, p. 35, pi. xxxi, figs. 1-4, 1898.