Page:Popular Science Monthly Volume 72.djvu/566

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 Pelion lyelli In the collection of the American Museum. Natural size

the lesser part of the skull went to Dr. Newberry, and in some way the other half of the slab containing the major portion of the cranial elements was obtained by Mr. W. F. E. Gurley and it is now in the collection of the University of Chicago. The illustration is made from the latter specimen. This form is peculiar in the possession of horns which projected backward over the neck. Jaekel suggests that these horns were tor the protection of the external gills, but the Microsauria, so far as we know, had no gills, at least in the adult state.

Geologically the record of the amphibians, as it has been given, is the correct one, but chronologically it is not. Long before a single specimen had been taken from the Linton beds Sir William Logan, in 1842, found evidences of amphibians in the Carboniferous of Nova Scotia in some footprints later named by Dawson Hylopus logani. These footprints Logan took with him to London and submitted them to the famous paleontologist, Sir Richard Owen, who unhesitatingly pronounced them to be "reptilian." Logan's discovery constitutes the earliest recognition of amphibians in the Carboniferous. A few years