As Dr. Fraas remarks, this discovery shows how closely analogous Ichthyosaurs were in form to fishes, and further justifies the title of "fish-lizards." He considers that they did _not_ visit the shore. The reader will find much valuable matter in Mr. Lydekker's paper, above referred to. The following extract refers to the question of their reproduction: "It has long been known that certain large skeletons of Ichthyosaurs from the Upper Lias of Holzmaden, in Würtemberg, and elsewhere, are found with the skeletons of one or more much smaller individuals enclosed partly or entirely within the cavity of the ribs [a specimen is figured]. Of such skeletons there are four in the museum at Stuttgart, two in that of Tübingen, one at Munich, and others in Gent and Paris. Of these, two in Stuttgart, as well as the two in Tübingen, contain but a single young skeleton, while one of those at Stuttgart has four, the Munich specimen five, and the remaining Stuttgart example upwards of seven young. Some of these young and, presumably, foetal Ichthyosaurs have the head turned towards the tail of the parent, while in others it is directed the other way. That these young have not been swallowed by the larger individuals within whose ribs they are found is pretty evident from several considerations. In the first place, their skeletons are always perfect. Then they never exceed one particular size, and always belong to the same species as the parent. Moreover, it would appear to be a physical impossibility for one Ichthyosaur of the size of the Stuttgart specimen to have had seven smaller ones of such dimensions in its stomach at one and the same time. We may accordingly take it for granted that these imprisoned skeletons were those of foetuses. It is, however, very remarkable, that, so far as we are aware, all the skeletons with foetuses belong to one single species; thus suggesting that this particular species was alone viviparous." It is to be hoped that further discoveries will be made, such as may finally settle this question. One would have expected that in some cases the young ones, if foetal, would be imperfectly developed. INDEX. A Æpyornis. Vid. Moa-bird. Agassiz, 27 "Age of Reptiles," 63, 107; "Age of Mammals," 147 Air, action of, 10 Allosaurus, 83 Ancients, ideas of the, 35, 61, 155, 195, 199 Apatosaurus, 70 Aqueous rocks, 14 Arbroath paving-stone, 26 Armadillo. Vid. Glyptodon. Articulata, 25 Atlantosaurus, 70 B Backbone of fishes, 49 "Bad Lands" of Wyoming, 157 Baker, Sir Samuel, on Crocodiles, 48; on Elephants, 215 Basalt, 14 Berossus, the Chaldæan, 34 Birds, fossilisation of, 19; ancestry of, 63, 109. Vid. Hesperornis, Moa. Blackie, Prof. J. S., on Ichthyosaurus, 37 "Breaks," 21, 147 Brontops, 160 Brontosaurus, 66; vertebræ of, 68; habits of, 69 Buckland, Dean, 37, 46, 53, 73, 75-77, 124, 126, 180 Buffon, 5, 223 C