this sea, but sufficient to show that it is "possible in the still bottom water, although such conditions in the Mediterranean do not seem to favor life."
The deepest water was found on the line from Admiralty Islands to Japan, one sounding giving the enormous depth of 4,575 fathoms, or five and a half miles. This is said to be the deepest trustworthy sounding yet made, excepting two by the Tuscarora off the east coast of Japan, where a depth 600 feet greater was found.
One of the results of this expedition has been to extend a knowledge of the fauna of the deep oceans, and the forthcoming work of Prof. Thomson will be brilliant with illustrations of new and beautiful forms.
The great voyage is divided into four sections. The first is from Sheerness, England, to the Cape of Good Hope, but by the very roundabout course of St. Thomas, Bermuda, Halifax, and St. Vincent. The second section is from the Cape of Good Hope to Hong-Kong by the way of Australia and the Polynesian Islands. The third section is from Hong-Kong to Valparaiso, touching at Japan, the Sandwich Islands, Tahiti, and Juan Fernandez. The fourth section is from Valparaiso to Sheerness, arriving on the 26th of May last.
Recently-Discovered Fossils.—In an appendix to the American Journal of Science for June, Prof. O. C. Marsh gives notices of a new sub-order of Pterosaurians, Pteranodontia, and of three new species of Odontornithes. The distinctive feature of the sub-order Pteranodontia is the absence of teeth (hence the name). The new genus Pteranodon is readily distinguished from any pterodactyls hitherto described by the cranial characters, which are well shown in a nearly perfect skull and portions of others in the Yale Museum. The cranium is very large, and the facial portion greatly elongated. There is a high sagittal crest which projects backward some distance beyond the occipital condyle. The maxillary bones are closely coössified with the premaxillary, and the whole forms a long, slender beak. There are no teeth or sockets for teeth in any part of the upper jaws, and the premaxillary shows some indications of having been incased in a horny covering. The lower jaws also are long and pointed in front, and entirely edentulous. In several other respects the jaws in this genus are more like those of birds than of any known reptiles.
From the same localities, and from the same geological horizon, the Upper Cretaceous of Western Kansas, which have yielded the specimens constituting the suborder of edentulous Pterosaurians, come the remains of the Odontornithes, or birds with teeth, and the two doubtless lived together in the same region. The remains of one of these birds with teeth indicate a bird fully six feet in length from the apex of the bill to the end of the toes. The femur and the tibia resemble those of some modern diving-birds, but the toes are shorter and stouter.
The Prehistoric Pig.—In an essay on "The Prehistoric Pig of Britain," Prof. Rolleston arrives at the following conclusions: 1. The domesticated pig of pre-Roman times he refers to the wild variety of Sus scrofa. 2. The Indian wild-hog (S. cristatus) differs mainly by the retention of structural conformations which are only temporarily respresented in the European wild species. 3. Taking the changes which domestication produces into account, S. Indicus he conceives to be a modified S. cristatus, and not derived from S. leucomystax, or other species. 4. The skull of a wild-sow from the alluvium at Oxford possesses such a combination of characters as to cause the author to hesitate in accepting the Torfschwein (S. scrofa), variety palustris of Rütimeyer, as a distinct species. 5. Simplicity of third molars in a large skull of the Bornean pig (S. barbatus) has no value. 6. The S. verrucosus, in its tear and cheek bones, differs from the S. barbatus, and these peculiarities obtained in the old Irish "greyhound pig" figured by Richardson.
Appropriation of Silica by Plants.—Prof. P. B. Wilson, of Washington University, Baltimore, having, in a chemical examination of the ash of grasses, discovered that the silica contained in such ash differs essentially from silica reduced from natural silicates—that, in fact, it had been assimi-
