260 The American Naturalist. [March 
compilers with no critical knowledge. We have already reviewed the 
numbers of Professor von Zittel’s work as they have appeared, and we 
now direct attention to the part which includes the first half of the 
Reptilia. In the arrangement of the class he adopts the following 
ordinal groups and names: Ichthyosauria, Sauropterygia, Testudinata, 
Theromora, Rhynchocephalia, Lepidosauria, Crocodilia, Dinosauria, 
Pterosauria. On this we observe that the name Sauropterygia is ante- 
dated by the Plesiosauria of DeBlainville, and Lepidosauria by both 
the Squamata of Merrem and the Streptostylica of Stannius. In the 
treatment of the subject Dr. von Zittel has incorporated the latest 
information from all sources, and has produced the best summary of it 
now extant. The work meets our approval more entirely than the 
parts devoted to the fishes and the Batrachia. In the Testudinata we 
the results of the recent work done by Dr. Baur, and in the 
Theromora much is derived from the writings of Seeley. Lydekker is 
extensively quoted for the Plesiosauria, and American authors are used 
where necessary. ‘The illustrations are numerous and excellent. 
The work of Dr. Déderlein is more compact than that of von Zittel, 
the families being represented by a few selected genera, no attempt 
being made to enumerate all of those which are known. The result is 
a work of less utility to the special student, but of more practical 
value to the reader who wishes to know only the capita rerum. Th 
system of the fishes is considerably in advance of that of the other 
text-books, since the supposed order of ‘‘Ganoidea’’ is not adopted, 
and the division Teleostomi is accepted as one of the primary divi- 
sions of fishes, a position to which it is undoubtedly entitled. We find 
the system of the Reptilia a little less full than that of von Zittel, but 
that of the Batrachia is less opem to criticism. The Mammalia are ex- 
cellent, and the latest information has been incorporated. 
The Manual of Drs. Nicholson and Lydekker is of especial impor- 
tance as the only work of the kind in the English language. We had 
occasion to review unfavorably the first edition of the work a few years 
ago, but we must give a different reception to this new third edition. 
The book has been completely rewritten, and greatly improved in 
every respect. The department of Vertebrata is, in fact, a new work, 
the excellence of which is guaranteed by the authorship of Dr. Richard 
Lydekker. The illustrations are numerous and good, and there is 
very little in the science which is not in some way referred to in the 
text. For any but the use of the book as one of reference, many of 
the genera are too briefly mentioned. The work is not without faults. 
The systematic, especially that of the fishes, is frequently not quite up 
