ICHTHYOSAURIAN REPTILES. 



515 



doubt as to the nature of the relationships of the Continental to the 

 British Ichthyosaurians. 



It need hardly be mentioned that the first Ichthyosaurs specifi- 

 cally described were obtained from the Lower Lias of our own 

 country, and there is consequently no sort of doubt as to the names 

 by which they should severally be designated. Very different, how- 

 ever, is the case with the species from the Upper Lias ; names having 

 been applied to specimens in this country and on the Continent, many 

 of which there has long been reason to regard as specifically identical, 

 although there has hitherto been great difficulty in obtaining decisive 

 evidence on these points. Dr. Fraas has, however, now enabled us 

 to judge for ourselves on these difficult questions, and has brought 



Fig. I.— Skeleton of an Ichthyosaur, showing the outline of the soft parts, together with a 

 restoration of the same. {From Fraas.) 



forward evidence to show that there is every probability of the 

 identity of the majority of the British and Continental species. 



Dr. Fraas commences his memoir with an interesting survey of 

 the history of the gradual acquisition of our knowledge of the 

 structure of the Ichthyosaurian skeleton, from the date of Sir Everard 

 Home's first memoir published as far back as 1814. We may 

 observe, however, that when stating that the name Ichthyosaurus 

 is antedated by Proteosamus of Home, the author appears to have been 

 misled by a similar statement in the British Museum Catalogue of 

 Fossil Reptiles ; the real fact being that the former name is three 

 years the earlier of the two. 



The historical portion of the memoir is succeeded by a dissertation 

 on the general structure and affinities of the Ichthyosaurs. Here 

 the author heartily endorses the views of Dr. Baur as to the close 



