ANNIVERSARY ADDRESS OF THE PRESIDENT. lxxxvii 



P. sivperstes, as being probably the last surviving representative of a 

 genus " which occupied so important a place in the fauna of the 

 Carboniferous and Permian epochs." The Rev. Mr. Brodie also 

 states that " another and entire fossil fish has been obtained from 

 the Keuper Sandstone, but that the possessor has not yet been per- 

 suaded to place it in the hands of a palaeontologist for examination 

 and description." He mentions also the discovery of more vegetable 

 remains, amongst which are several which appear to be the calyces 

 of some flowering plant. The occurrence of so many vegetable im- 

 pressions in beds so closely associated with those containing the fossil 

 fishes in this locality, and the similar occurrence of Posidonia minutely 

 now considered by some able palaeontologists as a Crustacean 

 (Estheria), seem to suggest a freshwater habitat for the genus Palaio- 

 niscus ; and I will only add that the analogy in anatomical structure 

 of extinct with existing fishes is not always sufficient to prove that 

 the medium in which they lived must have been the same. 



The next paper was one pregnant with interest, as it brought 

 before us proofs of a terrestrial fauna in the Purbeck region, which 

 had been previously represented only by the fossil mammifer named 

 and described by Professor Owen as Spalacotherium tricuspidens, a 

 small insectivorous form, referred with some hesitation to the Placen- 

 tal series. It was discovered by Mr. W. It. Brodie in one of the 

 dirt-beds of Durdlestone Bay, Purbeck ; and the same observer after- 

 wards found other mammalian remains, also in a dirt-bed, which he 

 forwarded to Professor Owen for description. Mr. Samuel H. Beclvles, 

 who had already gained much experience by his researches in Sussex 

 and the Isle of Wight, now entered on the field, and being encouraged 

 and assisted by the judicious advice of Sir C. Lyell, who has always 

 maintained that the non-discovery of the remains of terrestrial 

 animals is no decided proof that they had not existed, proceeded to 

 Swanage to commence that close and steady search for mammalian 

 remains which has resulted in the discovery of what would be con- 

 sidered a rich local terrestrial fauna, even in the present state of the 

 earth, some reptilian remains having been mixed with those of the 

 mammals. The whole collection has now been submitted to Pro- 

 fessor Owen for his final examination and description ; but in the first 

 instance they were wisely sent to Dr. Falconer, who, being able — as a 

 consequence, I am sorry to say, of frequent confinement to his house 

 by ill health — to devote his immediate attention to them, was in a 

 eondition to give Mr. Beckles useful hints in the progress of his search. 

 Dr. Falconer soon recognized no less than seven or eight genera 

 of Mammalia, some of them unquestionably Marsupials, both preda- 

 ceous and herbivorous, others, in Dr. Falconer's opinion, more pro- 

 bably Placental Insectivora, having affinities, more or less remote, 

 to existing types. Having been requested by Mr. Beckles to de- 

 scribe one of the most remarkable genera, as a contribution to the 

 Supplement of Sir C. Lyell's ' Manual,' then about to be published, Dr. 

 Falconer favoured the Society with a more detailed statement of the 

 result than was necessary for the former purpose. 



The genus Plagiaulace (being an abbreviation of Plagiaulaeodon, 



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