Geology and Palwontology, ' 43 
T)y Mr. Koken from the otoliths, but resembles in general the 
present fauna of the Gulf of Mexico, of the West Indies, and the 
Southern coasts of the United States, I'he dissimilarity of the fish 
faunas on both sides of the Atlantic existed, therefore, already during 
the earlier Tertiary. We are indebted to Mr. Koken for having de- 
veloped an entirely neglected subject, the study and determination 
of fossil fish otoliths, to such an extent that important conclusions 
can be derived. — 0. Meyer, 
Catalogue of Fossil Reptilia and Batrachia of the British 
Museum Pt. I., by Dr. Lydekker. In this volume we have what 
has been long needed, a synopsis of the fine collection of Brit- 
ish and such other European extinct reptiles of the orders Ornitho- 
sauria (Crocodilia), Dinosauria, Squamata and Rhynchocephalia, 
Avhich is embraced in the national museum of Great Britam. Th s 
synopsis is. like its predecessors, systematically arranged, and the 
text is enlightened wi h comments on the structural relations of the 
forms embraced in it. Many of the forms, especially of Dinosauria, 
described by English authors, have been hitherto in a state of ob- 
iirity to foreign observation, and a great deal is done 
vhi< h the 
mesozoic formations of Europe"^are so produ( tive. While we accord 
generally with the systematic views expressed by Dr. Lydekker, we 
must point out a few points of divergence. We cannot perceive the 
raison d'etre of an order Proterosauria. which the author, indeed, 
seems to rrgard as provisional. We do not believe that the Opistho- 
ooela (Sauropoda) is distinguishable as an order from the Crocodilia. 
In nomenclature, we find the two divisions of the true Dinosauria 
to accord exactly with our own, and not with those of Professor 
Marsh, yet the names of the latter author are adopted. As 
usual, we find some generic names adopted, which were never 
characterized, as Tractiodon instead of Hadrosaurus. Finally, 
we must make an appeal on behalf of the name Belodon for the 
genus usually so called, as against the prior name of Phytosaurus. 
Phytosaurus for an entirely carnivorous animal is a g' oss misnomer, 
and is nauseating to the scientific stomach, Not only this, but the 
typical specimen exhibits only min ral casts of the pulp cavities 
m place of teeth, so that name belongs to mineralogy rather than 
to palfeontology. In case Belodon has been previously otherwise 
used, there are other available names, as Centemodon Lea. for in- 
stance. 
In concluding this review, we must record our appreciation of the 
author's method of ch ar definitions for all divisions he proposes and 
adopts, a custom which is the necessary basis of all ixood taxonomic 
work. — E. D, Cope. 
