
646 The American Naturalist. [July, 
yet be discovered, but it has not been as yet; and it will not be soon 
observed with the embolomerous structure. 
The author’s adhesion to the law of priority in specific and generic 
names contributes much to the simplification of nomenclature. He is 
not as strict in the matter of family names. We cannot agree with 
him in changing a name as preoccupied, so long as it differs from the 
supposed preoccupier by one letter. This is not preoccupation.—C. 
A. S. Woodward’s Fossil Fishes.*—The fine collection of 
fossil fishes contained in the British Museum has been at last utilized 
as the basis of a systematic work. No better appointment could have 
been made for the accomplishment of this purpose than Mr. A. Smith 
Woodward, whose abilities as a systematic zoologist have been amply 
tested in this difficult field. The first part of the catalogue is devoted 
to the Elasmobranchii. Two hundred and ninety-six species are con- 
tained in the museum collection, which is only a part of those actually 
known. The value of the work is greatly enhanced by the reference 
list of all described species given under the head of each genus. Of 
the above species, twenty-four are included under the Ichthyotomi, of 
which fourteen are Pleuracanthide, and the remainder Cladodontide. 
The systematic position of the latter family is for the first time thus 
indicated. The doubts expressed as to the segmentation of the skull 
of Didymodus, expressed in this place by Mr. Woodward, have been 
since set at rest by an inspection of the specimens themselves, as he 
acknowledges in his report on American collections published in the 
Geological Magazine at a later date, 
In the second part of the work Mr. Woodward takes in hand the . 
question of the systematic relations of the fishes in general. He dis- 
cards the division Ganoidei as unavailable, and adopts the subclasses 
Elasmobranchii, Holocephali, Dipnoi, and Teleostomi, as has been 
done in this country. e does not adopt the Agnatha, but accepts 
the superorder Ostracodermi * Cope, which, according to some authors, 
represents the formér in the Paleozoic formations, and places them as 
a fifth subclass of the Pisces. This is a great advance over previous 
views held in Europe, and it now remains to be seen whether the 
opinion that the Ostracophori are outside the class of fishes is to be 
sustained by further discovery or not. 
2 Catalogue of Fossil Fishes in the British Museum. By Arthur Smith ——— 
Part I., 1889; Part II., 1891. Published by the trustees of the ‘British Muse 

the apparent necessity f 
5 
3 This name was ee ec Gill i in 1861 s the Scleroderm enm Sohon. 3 regret 




