70 



SCIENCE. 



[N. S. Vol. VIII. No. 185. 



specialized forms and not primitive ones 

 presenting transitions from the fishes. His 

 view is now probably very generally ac- 

 cepted. 



A number of his papers related to the 

 structure and the systematic position of the 

 leather-back turtle, Dermoehelys. He op- 

 posed strongly the views of Cope, Dollo, 

 Boulenger and Lydekker that this reptile 

 ^jf iifoms a suborder distinct from all other liv- 

 ing tortoises. He regarded it as belonging 

 to merely a highly specialized branch of the 

 Pinnata, a group which contains our living 

 sea- turtles. 



The structure and relationships of the 

 Mosasauridse form the subject of several 

 interesting papers. In opposition to Pro- 

 fessor Cope, who maintained that these 

 extinct reptiles bore special relationship to 

 the snakes. Dr. Baur held that they were 

 true lizards, closely related to the Varan- 

 id£e, but modified for adaptation to an 

 aquatic existence. An excellent paper on 

 the structure of the skull of the Mosasau- 

 ridse was published in the Journal of Mor- 

 j)Jiology for 1892. 



As early as 1886 Dr. Baur wrote a paper 

 on the homologies of the bones of the otic 

 and temporal regions. His interest in the 

 subject never relaxed and some of his latest 

 papers were written in a discussion of the 

 subject with Professor Cope. 



In the same year above mentioned, 1886, 

 Dr. Baur became interested in the mor- 

 phology of the vertebral column, and he 

 published a paper of considerable length in 

 the Biologisches Centralblatt of that year, 

 stating his conclusions. He gave his adher- 

 ence to the opinion of Cope, who held that 

 the vertebral centrum in all the Amniota 

 has developed from the pleurocentrum, an 

 element which is found distinct in the Ste- 

 gocephali. He found confirmation of his 

 views in the vertebral axis of the Pelyco- 

 saurian reptiles, in Sphenodon, certain liz- 

 ards, birds and even mammals. He ad- 



vocated the same views in one of his latest 

 papers. 



In the Ame7-ican Naturalist for May, 1891,. 

 occurs an important paper by Dr. Baur on 

 the reptiles known as the Dinosauria. In a^ 

 characteristic manner he gives the history 

 and the literature of the subject and his own 

 conclusions. His opinion was that ' the 

 Dinosauria do not exist. ' He believed that 

 this group is an unnatural one, and is made 

 up of three special groups of archosaurian 

 reptiles which have no close relation to one 

 another. 



Two of Dr. Baur's most important later 

 efforts are probably one entitled ' The Ste- 

 gocephali, ' a phylogenetic study, published 

 in the Anatomischer Anzeiger for March, 1896,. 

 and one, a joint paper with Dr. E. C. Case, 

 having the title ' On the Morphology of the 

 skull of the Pelycosauria and the origin of 

 the Mammalia,' and appearing in the 

 Anatomischer Anzeiger, 1897, pages 109-120. 

 In the first mentioned paper Dr. Baur com- 

 pares the skeletal structure of the Stegoce- 

 phali with that of various fishes and comes 

 to the conclusion that the Batrachia took 

 their origin from the Crossopterygia, rather 

 than from the Dipnoi. The second paper 

 was based on the fine materials collected by 

 Dr. Case in the Permian formation in Texas. 

 The authors concluded, on the one hand, 

 that the Pelycosauria are closely related to 

 the Phyuchocephalia and that, on the other 

 hand, they could not have been the ances- 

 tors of the mammals. The authors were 

 inclined to regard the Gomphodoutia as the 

 ancestors of the mammals. 



After Dr. Baur's return from the Gala- 

 pagos Islands, he devoted a considerable 

 portion of his attention to the study and 

 discussion of the problems which arose from 

 the examination of the materials which he 

 had there collected, and which had to a great 

 extent been turned over to specialists. His 

 conclusion with regard to the origin of those 

 islands was that they had originally been 



