244 Eminent Living Geologids — Dr. R. H. Traquair, F.R.S. 



patronage of which is vested in the Trustees of that institution, for 

 two periods of five years each, namely, from 1883 to 1887 inclusive 

 and from 1896 to 1900 inclusive. In this capacity he had to deliver 

 each year a course of twelve lectures, and naturally the subjects which 

 he chose for his lectures were always palaeontological. 



Besides by the specimens of fossil fishes under his charge in the 

 museum at Edinburgh, Dr. Traquair was much assisted in the way of 

 material by successive Directors-General of the Geological Survey 

 (Sir A. C. Ramsay, Sir A. Geikie, and Dr. Teall), who placed at his 

 disposal for description the fish-remains collected by the Survey in 

 Scotland, some of his best material having come to him from that 

 source. 



At the time of his leaving for Edinburgh he married the daughter 

 of Dr. "William Moss, of Dublin, and Mrs. Traquair prepared a 

 beautiful series of drawings of Palaeoniscid fishes to illustrate some 

 of his works. 



Dr. Traquair's original writings appear chiefly in the Transactions 

 of the Royal Society of Edinburgh, in the Proceedings of the Royal 

 Physical Society of Edinburgh, in the Geological Magazike, in the 

 Annals and Magazine of Natural History, and in the volumes issued by 

 the Palasontographical Society. As he always has consistently main- 

 tained that palaeontology is simply a part of biology, his own work was 

 from the beginning based on morphological structure and not on the 

 mere outline of body or configuration of scales and teeth. He showed 

 from their structui'e that the Palseoniscidas were more allied to Polyodon 

 than to the Lepidosteoid Ganoids, and that consequently their place 

 was with the Sturgeons (Acipenseroidei), and that the Platysomidae 

 were a specialized offshoot from the Palaeoniscidse. Indeed, his work 

 on these two families may be said to have given the deathblow to the 

 Agassizian idea of the classificatory importance of the external forms 

 of scales. He was the first clearly to prove that the Devonian genus 

 Cheirolepis was not Acanthodian but Palaeoniscid, though this had 

 been already hinted at by previous writers. In like manner he settled 

 the question as to Bipterus being referable to the Dipneusti, and 

 showed that it agreed in all essential points of structure. He 

 described the remarkable fish-fauna collected by the Geological Survey 

 of Scotland from the Upper Silurian rocks of Lanarkshire and Ayr- 

 shire, and showed that the Coelolepidaj, though in his opinion 

 probably derived from an Elasmobranch source, were not sharks but 

 Heterostracan Ostracodermi. And the Ostracodermi he divided into 

 four families, viz., the Coelolepidae {Thelodus and LmiarMa), the 

 Psammosteidae (Psammosteus), the Drepanaspid^e {Prepanaspis), and 

 the Pteraspidae {Pteraspis, etc.), and showed how that the mail-plates of 

 the three last families were evidently formed by the fusion of the small 

 Ccelolepid scales with each other and with hard tissue developed in 

 a deeper layer of the skin. He maintained that the Osteostraci were 

 more nearly related to the Heterostraci than had previously been 

 supposed, the minute tubercles covering the outside of the dermal 

 plates of Cephalaspis being suggestive that the superficial layers of 

 these plates were also formed by the fusion of Ccelolepid scales. He 

 also devoted special attention to the Asterolepidae or Pterichthys family, 



