THE ADVANCE OF SCIENCE 105 



gams has been practically bridged over by the discovery 

 that certain fern-like plants of the Coal Measures 

 the Cycadofilices, supposed to be true ferns, are really 

 seed-bearing plants and not ferns at all, but phanerogams 

 of a primitive type, allied to the cycads and gymno- 

 sperms. They have been re-christened Pteridosperms 

 by Scott, who, together with F. Oliver and Seward, 

 has been the chief discoverer in this most interesting 

 field. 



By their fossil remains whole series of new genera 

 of extinct mammals have been traced through the 

 tertiary strata of North America and their genetic 

 connections established ; and from yet older strata of 

 the same prolific source we have almost complete know- 

 ledge of several genera of huge extinct Dinosauria of 

 great variety of form and habit (fig. 25). 



The discoveries by Seeley at the Cape, and by Ama- 

 litzky in North Russia of identical genera of Triassic 

 reptiles, which in many respects resemble the Mammalia 

 and constitute the group Theromorpha, is also a pro- 

 minent feature in the palaeontology of the past twenty- 

 five years (fig. 26). Nor must we forget the extraordinary 

 Devonian and Silurian fishes discovered and described by 

 Professor Traquair (figs. 27 and 28). The most impor- 

 tant discovery of the kind of late years has been that 

 of the Upper Eocene and Miocene Mammals of the 

 Egyptian Fayum, excavated by the Egyptian Geological 

 Survey and by Dr. Andrews of the Natural History 

 Museum, who has described and figured the remains. 

 They include a huge four-horned animal as big as a 

 rhinoceros, but quite peculiar in its characters the 

 Arisino'itherium and the ancestors of the elephants, a 

 group which was abundant in Miocene and Pliocene times 

 in Europe and Asia, and in still later times in America, 



