+ 
The Fossil Elasmobranch Fishes. 367 
In the preparation of the Catalogue, which is much more than a 
classified compilation of families, genera, and species, the author 
has studied the best works of the latest writers on the Taxonomy 
and Morphology of the group, whether paleontological or zoological, 
and with manifest advantage. He adds a few brief comments on 
some systems of arrangement hitherto proposed, and on a few of the 
various opinions regarding the affinities of certain forms. The 
volume also contains many valuable original descriptions, observa- 
tions, and revisions of importance. The aim and scope of the work 
is related in the opening paragraph of the Introduction, which we 
reproduce. The author states: ‘The present volume being the 
first attempt at a systematic treatment of the Paleontology of the 
Elasmobranch fishes, it seems a fitting occasion for briefly reviewing 
_ the bearing of the newly collected evidence upon the various results 
that have already been attained in the study of the existing members 
of this great subclass. Notwithstanding its imperfections, Palzon- 
tology must necessarily be employed as the test—if it be not adopted 
as the basis—for all morphological and taxonomic speculations; and 
though the pages of the Catalogue may indicate extreme imperfection 
in our knowledge of the past history of most groups, there are still 
a few well-ascertained facts which may be already profitably dis- 
cussed with reference to the conclusions of recent Zoology.” 
“It is therefore proposed :—firstly, to enumerate the principal 
stages by which the most modern schemes of classification of the 
group have been elaborated; secondly, to summarize the known 
and available resources ; thirdly, to recapitulate the more important 
paleontological results ; and lastly, to discuss these results in the 
light of modern theories of taxonomy.” 
Under the heading “Taxonomic Deductions from the Study of 
Recent Hlasmobranchs,” the author gives a brief summary of the 
diverse classifications, and the varying terminology adopted or 
proposed by naturalists of repute, to distinguish the existing 
fishes assigned to the cartilaginous group; the following being 
the most important, commencing with Willughby and Ray, 
who “inaugurated the era of modern Ichthyology in 1686.” 
These authors “assigned to the Pisces Carrinacinet, the Lampreys, 
Sharks, Rays and Sturgeons.” This arrangement was accepted 
by Artedi (1788), who made the group an “order” named 
CHonpRoptEryGi. It was afterwards adopted by Linnzus, who 
enlarged the group by the addition of other forms, “and proposed 
the new term of Ampuinpia Nantes.” In 1806 Duméril, following 
Lacépede, who had returned to Artedi’s conception of the Chondro- 
pterygu, proposed the name of Trimatopnas for the fishes “ possessing 
neither operculum noropercular membrane,” to contain two “families ” 
which he termed Cyclostomes and Plagiostomes. “The latter group 
comprised the Sharks and Rays,” the Chimeroids being “placed far 
apart.” Cuvier later on added the Chimzroids to the Plagiostomes 
_and renamed the group Selachiens. Bonaparte (1832-1841) « pro- 
posed to elevate this group into a subclass of Hlasmobranchii, the 
two subdivisions to be regarded as orders and known respectively 
