316 Revieics — Barhas's Illustrated Guide. 



the larger proportion of which have been discovered within the last 

 few years. 



We wish Mr. Barkas had inserted, in addition to the list of 

 genera, a list of all the species of vertebrate remains found in this 

 locality, believing that these numbers would be considerably added 

 to ; should his book reach a second edition, we trust this important 

 defect will be remedied. 



On referring to the last edition of Prof. Morris's Catalogue of 

 British Fossils, published in 1854, w© find only twenty-nine genera, 

 containing sixty-four species, of Fossil Fishes recorded as then known 

 in the whole of the Coal-measures of Great Britain and Ireland ; 

 and many of these are entirely wanting in the Northumberland beds. 



The only repfilian genus there recorded (Parabatrachus) is now 

 cancelled ; for the specimen upon which it was founded, which is 

 preserved in the British Museum, has been long known to be the 

 inner view of the maxillary of Megaliclithys. 



Of the Fossil Fishes, Glimaxodus ovatus, Barkas, a Carboniferous 

 Limestone genus, was first discovered by the author in the Coal- 

 measures, and was originally described by him in the pages of this 

 Magazine, Vol. V. p. 495 ; see also Geol. Mag., Vol. VI. pp. 42, 

 381. Of the genus Ctenodus ten species have been founded by Atthey 

 and others upon teeth or other remains from the Newcastle Coal- 

 beds. Ctenodus tubercidatus, Atthey, is figured in Geol. Mag., Vol. 

 VI. p. 314, PL IX. This genus has an especial interest, owing to 

 its close affinity to Ceratodus, a genus which first appears in the 

 Trias a,nd is now found living in some of the rivers of Australia. 



Archichthys and OrtJiognathus have hitherto been recorded as found 

 only in the Northumberland beds. 



Of the Amphibia we have eight or nine genera which are here 

 first described and figured ; and the author believes that Ortliosaurus 

 pachycephalus, Barkas, are the remains of a true reptile. The species 

 is founded upon a nearly perfect cranium, of which he gives ex- 

 cellent figures of the natural size. He says : " In general form 

 and configuration, in the position of the orbits, in the absence of a 

 parietal foramen, in the strength of the quadrate bones, in the 

 freedom of the palate and vomer from dentition, and in the form of 

 the maxilliary bones, the cranium of Ortliosaurus very closely re- 

 sembles that of a modern crocodile." Should these views be con- 

 firmed by further investigation, these remains will be important as 

 being those of the first true reptile found below the Permian, for the 

 natural position of Prof. Marsh's Eosaurus from the Coal-fields of 

 Nova Scotia is still doubtful. 



The so-called mammal jaw we pass by as scarcely worthy of notice : 

 it is founded upon a fragment so imperfect and obscure that it is im- 

 possible to base any satisfactory determination upon it. 



Two well-marked forms of Ic^m'ies are described and figured from the 

 lower sandstone of the Carboniferous Limestone of Northumberland. 



The book is well printed, and is accompanied by an excellent atlas 

 of ten folio plates, eight of which are folding, containing 250 figures. 

 Many of these are of magnified microscopic sections, the otliers are 

 of the natural size. 



