92 NATURAL SCIENCE. apr.l, 



other duties that prevent the carrying out of his agreement, the 

 material ought to be at once handed over to some competent 

 colleague who will render it available to science. 



Of the extinct allies of the recent Ceratodns we have learned a 

 little more during the last twenty years. In 1891, indeed, the greater 

 part of the skull of the true Triassic Cevatodtis was described in 

 Austria' ; and some years previously a tail had been found in the 

 Upper Trias of Wilrtemberg. Teeth of the same genus have also 

 been discovered in Western North America and South Africa. It 

 now appears from Teller's memoir on the Austrian specimen, that, 

 although the true Ceratodns of the Triassic period was very similar to 

 the fish still living in Queensland, there are generic differences ; and 

 it is proposed that the recent fish should henceforth be termed 

 Epiceratodiis. The name Neoceratodns would have been more appro- 

 priate, but that has been already used for an ally in New Guinea. 

 The fossil, so far as known, differs from the recent fish in the greater 

 extent of the ossification of its skeleton. 



Speaking of the extinct Dipnoan Fishes, reminds us of the 

 remarkable change in the ordinary conceptions of this sub-class that 

 certain palaeontologists are inclined to introduce. In the second part 

 of the Catalogue of the Fossil Fishes in the British Miiseiun, published last 

 year, Mr. Smith Woodward hazarded the suggestion that in early 

 Palaeozoic times some of the tribes of Dipnoan fishes were as highly 

 specialised in comparison with the Cevatodns type as are the modern 

 Teleostei compared with the Fringe-finned Ganoids from which 

 they are doubtless descended. In a new number of the Pyoceedings of 

 the United States National Museum (vol. xiv., pp. 449-456) just received, 

 Professor E. D. Cope describes the skull of the Devonian Macropetal- 

 ichthys, and is in favour of the same theory. Indeed, so far as the 

 facts are known, the race of Devonian armour-plated "ganoids," of 

 which Coccosteus, Homosteus, and Dinichthys are the best preserved 

 genera, have the cartilages of the upper jaw fused with the skull, and 

 are comparable only with the Dipnoi in the arrangement of their 

 head-shield and dentition. The supposition that the Dipnoan fishes 

 attained to an extreme degree of specialisation at the time when they 

 were a dominant type of life is quite in accordance with known laws ; 

 and the fact that none but the more generalised forms survived until 

 later periods, is also what might have been expected. We await 

 with interest further discoveries on the subject. 



Professor A. Giard has just published a brief account of a 

 small turbot, in which the original bilateral symmetry of the fish is 



^ F. Teller, " Ueber den Schiidel eines fossilen Dipnoers, Ceratodus sturli, sp. 

 nov.," Abhandl. k.k.gcol. Reic'tsanst., vol. xv., pt. 3, 1S91. 



