Page:Quarterly Journal of the Geological Society of London, vol. 29.djvu/607

1873.] When we are favoured, with the description and figures of the Odontornithes by their accomplished discoverer we shall possess grounds for judging of the ordinal and higher relations of affinity between the Eocene toothed bird and the Cretaceous Ichthyornis. But the indications already vouchsafed by that active and indefatigable palæontologist suffice for an opinion of their specific and generic distinctness.

Odontopteryx has the orbits well within the limits of the hinder half of the skull; the lower jaw, though no doubt "long," has the rami too deep to bear the term "slender;" the teeth are separated by spaces which would not permit of their being reckoned as "quite numerous;" they are not implanted in sockets, but are represented by alveolar processes of the bone. It is true that some of them are "small," and all are "compressed and pointed;" but they are not "all similar" in respect of size: one, two, or three small teeth are interposed to the single, widely separated, large laniaries; finally, all the preserved teeth of Odontopteryx incline more or less forward instead of "backward."

Fig. 1. Eight-side view of the preserved part of the skull of Odontopteryx toliapicus, Ow.

2. Left-side view of do. do.

3. Hind or occipital surface, with right tympanic bone: v, portion of atlas.

4. Upper view of the preserved part of the skull of Odontopteryx toliapicus, Ow.

5. Preserved dentigerous parts of right side of both jaws; twice the natural size.

6. Preserved dentigerous parts of left side of both jaws; twice the natural size.

7. Outline of entire skull, conjecturally restored, from above.

8. Outline of entire skull, conjecturally restored, from the right side.

Fig. 1. View of a longitudinal section of the denticle, magnified 35 diameters and reduced one half.

2. View of a portion of the same section, magnified 250 diameters and reduced one half.

Mr. had given much study to the Pterosaurians, to which the author had indicated the affinities of Odontopteryx. He had in Ornithocheirus Oweni found what appeared to be identical structure with that of the bird; and it therefore appeared to form a new genus of Pterosaurians. Both in the frontal and occipital regions of the skull he recognized affinities to Ornithocheirus; but it presented even more distinctly marked reptilian affinities. The position of the brain was also quite as far back in the skull; and the quadrate bone also presented curious analogies, so much so as to be almost identical.