Bibliographical Notices. 139 



from the recent Cestracion Philippic or Port Jackson shark, a fish 

 most valuable to palaeontologists as being the only existing type of 

 the family Cestraciontidae, so extensively distributed through our fos- 

 siliferous strata, from the Silurian to the Chalk both inclusive." 



Of the Ganoid order are the new genera Pomognathus, Ag., pro- 

 posed by Agassiz, from the lower jaw extending so far back towards the 

 opercular bones ; Prionolepis, Egerton, allied to Aspidorhynchus, but 

 differing in the arrangement and articulation of the scales ; and Pha- 

 codus, Dixon, so named from the kidney-bean-shaped character of 

 the teeth. 



In the Ctenoid order are briefly noticed Berycopsis and Homo- 

 notus, Ag., new genera allied to Beryx, and Stenostoma, Ag., alhed 

 to Rhacolepis. 



In the Cycloid order are the new genera Pachyrhizodus and TomO" 

 gnathus. The affinities of the latter genus are unknown ; the only 

 portions discovered having been jaws and portions of the cranium. 



The elaborate descriptions of the Corals by Mr. Lonsdale furnish 

 much valuable matter in the detailed notes accompanying each spe- 

 cies and their comparison with allied forms. Eight species of eocene 

 Anthozoa are described. Among the cretaceous Anthozoa five new 

 genera are described, viz. Monocarya^ Biblasus, Axogaster^ Epi- 

 phaxuniy and Splnopora. Among the Bryozoa Mr. Lonsdale includes 

 six new genera, viz. Desmeopora^ Petalopora, Holostoma^ Siphonio- 

 typhluSyHomoeosolen, sindAtagma, besides some new species belonging 

 to established genera. By short extracts merely from this important 

 part of the volume, we should not have conveyed to the reader the 

 minute accuracy of description embodying the careful examination of 

 the species noticed ; but it points out how cautious our determinations 

 should be in the specific forms of either the Anthozoa or Bryozoa. 



Among the fossils of the Chalk formation, the sea-urchins and star- 

 fishes are generally considered more interesting, and arrest the atten- 

 tion of the collector ; of these many new and beautiful forms are fully 

 illustrated in the work before us. Nor have the Echinodermata been 

 neglected in the researches of the zoologist, many valuable physio- 

 logical and systematic memoirs having of late appeared in elucidation 

 of their recent history, which has materially assisted the investigation 

 connected with the relations of the existing and extinct forms. 



The family Asteriadse, which until recently was considered to have 

 commenced with the Oolitic period, have, through the labours of 

 Prof. Sedgwick, Mr. Sharpe, and the Geological Survey, been found 

 in strata of Silurian age, both in Westmoreland and North Wales ; and 

 what is equally interesting, they are referred to the genus Uraster, 

 the members of which, although found in all parts of the world, are 

 more characteristic, by their abundance and predominance, of the ap- 

 proach to the Arctic or Antarctic regions. Prof. E. Forbes, in his 

 valuable and scientific Synopsis of the British Fossil Asteriadae, pub- 

 lished in the * Memoirs of the Geological Survey,' p. 462, states — 



" It is very remarkable that all the true starfishes, hitherto dis- 

 covered in a fossil state in the sedimentary deposits of the palaeozoic 

 oceans, appear to belong to this genus Uraster, whilst the majority 



