May 17, 1912] 
was Philip Leidy, the hatter, on 3rd street above 
Vine; my mother, Katherine Mellick, but she died 
a few months after my birth, and my father mar- 
ried her sister Cristina, who was all in all to me, 
the one to whom I owe all that I am. At an 
early age I took great delight in natural history, 
of which I have reason to think I know a little, 
and a little of that little I propose to teach you 
to-night. 
One does not need to glance at the splendid 
head on the opposite page to realize that this 
great naturalist, whose “ Rhizopods of North 
America,” is one of our finest biological clas- 
sics, was echt, in the exquisite Hmersonian 
sense of living “from a great depth of being.” 
There are a few typographical errors here 
and there, but these things are of little conse- 
quence in a work which deserves to be in the 
library of every physician interested in the 
medical history of his country, and which will 
undoubtedly prove a valuable reference book 
in working scientific and public libraries. 
F. H. Garrison 
SURGEON GENERAL’S LIBRARY 
A Revision of the Cotylosauria of North 
America. By E. C. Casrt. Washington, 
Carnegie Institution, Publication No. 145. 
1911. Pp. 122, 14 plates. 
It is now more than thirty-six years since 
the first Permian or Permo-Carboniferous 
reptiles were made known from North Amer- 
ica by the late Professor Cope, who until his 
death twenty years or more later published at 
frequent intervals papers dealing with Paleo- 
zoic land vertebrates, coming chiefly from 
the famous deposits in northern Texas. As a 
pioneer, his work, here as elsewhere, was, of 
necessity, largely based upon fragmentary 
and imperfect material, material largely ob- 
secured by an obdurate matrix that only long 
and skilful preparation could remove. Few, 
if any, forms were known to him in anything 
approaching perfection or even completeness. 
As an inevitable result he left the subject in 
more or less confusion, notwithstanding the 
many important facts which he discovered. 
Many of his types were never figured nor even 
adequately described. In more recent years, 
beginning with Professor Case’s collection in 
SCIENCE 
779 
Texas in 1897, the additions to our knowledge 
of these old land vertebrates made by him and 
others have been very considerable and of 
profound importance in paleontology. But 
much of the confusion and doubt regarding 
many of the original types, for the most part 
preserved in the American Museum of New 
York City, could only be removed by a care- 
ful revision of the whole group, based upon 
original specimens. This Professor Case has 
given us of the so-called order Cotylosauria 
in the present paper. At the present time 
there is, perhaps, no group of vertebrates of 
deeper interest to the student of evolution 
than the primitive reptiles and amphibians of 
the later Paleozoic, the forms from which all 
later vertebrates, save the fishes, have been 
derived. The many problems of the evolution 
of the Amphibia, and the origin and “ radia- 
tion” of the Reptilia, are, until other fields 
have been discovered, dependent chiefly if not 
almost wholly on the Permo-Carboniferous 
deposits of Texas and the Rocky Mountains. 
No classification of the reptiles and amphib- 
ians will ever command any great degree of 
respect until these faunas have been well 
worked out; and, inasmuch as many of the 
problems of these groups are fundamental 
ones in many respects for all higher verte- 
brates, the interest attached to such studies as 
the present may be easily understood. 
Professor Case did a very acceptable piece 
of work in his revision of the Pelycosauria, or 
the higher reptiles of the same fauna, pub- 
lished a few years ago. In the present work 
he has revised systematically and morpholog- 
ically the numerous genera and species that 
have been proposed of the cotylosaurian rep- 
tiles, a group usually called an order though 
not distinguishable by very important char- 
acters from the Pelycosauria or Theromorpha. 
The chief value of the paper is the informa- 
tion given of the fragmentary and often un- 
recognizable types of Cope, as interpreted in 
-the light of a more advanced knowledge of 
the group, by descriptions, comparisons and 
illustrations. Not much new material has 
been described nor have many new forms been 
added that had not been published by himself 
