On the electrolytic estimation of cadmium

IN a previous article (vol. xvi, p. 411, Nov., 1878), the writer gave a short account of the geological horizon and accompanying fossils of the J UJ'assic Dinosaurs recently found in the Rocky Mountains j alld also stated the more important characters of the gigantic ~'auropoda, as illustrated mainly by the genus j[01"OSa'1J,r'1J,8. In the present communication, this group is further elucidated by a comparison of' the structure in some other American genera, especially Apatosaurus and Allantosa1.J.1'us, to whieh belong the largest reptiles hitherto discovered. The carnivorous enemies of' tbis group are also bl'iefly desrribed. The pelvis of Dinosaurians, hitberto so little known, is illustrated by new examples, and by the corresponding parts in some recent birds.