50 The Progress of Zoology. | Jan., 
reptiles—a view which is strengthened by the analogy drawn from 
other classes of Vertebrata; the Mammals have their inferior sub- 
division, the Odtocoids, or semi-ovoviviporous species (Marsupiahia 
and Monotremata); the birds have thew inferior sub-division, the 
Erpetoids (Archzeopteryx), and between ordinary Reptiles and Fishes 
there are Amphibians, forming a similar hypo-typic subdivision of 
reptiles. 
: The editor of the ‘ Record’ has taken his share of the work, and 
appears also as the compiler of the copious article on Fishes, a sub- 
ject in which he is also a great authority. His catalogue of the 
fishes of the British Museum is an important monument of his 
labours in this division of Zoology. In this catalogue, which forms 
a complete handbook to Ichthyology, all the species known are 
described and systematically arranged. Up to the present time, five 
volumes of this catalogue have been published, the first three con- 
taining the 3,481 species of Acanthopterygn at present known, the 
fourth and fifth describing nearly 2,000 other species; but the work 
is still incomplete, upwards of 8,000 species bemg known, nearly 
equally divided between freshwater and salt. But in the European 
fauna, the ratio between freshwater and marine species is as one to 
three. Another important work is a collected account of the 
Ichthyology of the Kast Indian Archipelago, by M. P. Bleeker, pub- 
lished by the Dutch government. our volumes im folio have ap- 
peared. Dr. Bleeker has spent twenty years in this study, and the 
present work is chiefly a republication of descriptions, accompanied 
by very accurate plates from drawings made in India. The fishes 
of Finland, too, have been described by Herr Malmgren, who pro- 
pounds theories of the specific identity of the different European 
Salmonoids, which are strongly combated by the editor. Among the 
contributors of papers to the hterature of Ichthyology, Dr. Ginther, 
Mr. Gill, and Dr. Bleeker figure conspicuously; and Mr. Gill’s 
theory of the typical Leptocephali being the larval form of young 
congers, coupled with Agassiz’ views of the metamorphoses of fishes, 
is not the least noticeable part of their history to which attention 
has recently been called. Mr. Gill promises a more extended 
memoir upon this subject, and the avowed purpose of Agassiz’ 
journey to South America is to study the metamorphoses of the 
fishes of the Amazon, so that we may hope for more ight upon this 
very remarkable subject. 
The article upon “ Mollusca” is supplied by Dr. Eduard von 
Martens, himself a copious contributor to the literature of the sub- 
ject. By far the greater portion of the publications on this class of 
animals is devoted, observes Dr. Von Martens, to descriptions of 
species belonging to types more or less previously known, and more 
especially of their shells, as is usually the case in this department of 
Zoology. The most important work at present in progress is Lovell 
