NOVEMBER 10, 1899. ] 
the forearm movement proved slightly in- 
ferior to the more practiced finger move- 
ment, and even to the full arm movement. 
In this particular the full arm movement 
would, with practice, probably be the best 
of the three. But in uniformity of slant, 
the forearm movement was far superior to 
the others. There were a smoothness and 
grace in the tracings of this movement that 
were quite absent from the rest. 
These analytical laboratory experiments 
were obtained with a high degree of agree- 
ment from a considerable number of indi- 
viduals. As to the results of the suggested 
movement in actual writing, little more can 
at present be asserted than that the move- 
ment is entirely practicable. The few who 
have tried it are pleased with the results. 
The writer of this article has himself 
adopted it largely, and finds realized the 
advantages that the laboratory experiments 
gave reason to expect. Rapid writing is 
freer and more legible, showing no tendency 
to degenerate into the flat scrawl. Less 
fatigue is felt; and the muscles employed, 
though not so large as those of the full arm 
movement, are large enough to avoid the 
tendency to cramp. The uniformity of 
slant gives the page a neat appearance. 
The alignment is satisfactory. The posses- 
sion of two movements is at times a great 
source of comfort. Finally, from the rela- 
tive facility with which the left hand was 
found to acquire the various movements, 
as well as from the fact that the wrist 
movement is made by the simplest muscu- 
lar coordination, it seems altogether prob- 
able that the wrist movement would possess, 
over the complex finger movement, the ad- 
vantage of being more easily learned. 
R. 8. Woopwortu. 
A CENSUS OF THE FOSSIL VERTEBRATA OF 
NORTH AMERICA. 
Tue writer has been able to make such 
an examination of the literature appertain- 
SCIENCE. 
681 
ing to fossil vertebrates, that he feels justi- 
fied in making a statement regarding the 
number of genera and species which are 
known to occur in North America north of 
Mexico. The writer is not aware that any 
one else has yet prepared a list of the spe- 
cies of all the groups, and apparently the 
paleontologists themselves have very vague 
ideas regarding the number of known spe- 
cies, outside of the groups which they are 
themselves studying. 
It is, of course, recognized that no two 
men in preparing such a list would arrive 
at the same results, since their ideas would 
undoubtedly differ more or less regarding 
what are to be considered tenable genera 
and species. In determining whether or 
not reputed species are to be reduced to 
synonymy, the writer has in most cases ac- 
cepted the results of the investigations of 
other workers, where such results have been 
expressed clearly and definitely ; while in 
cases of doubt a conservative course has 
been followed, it being held that it will 
cause less confusion in nomenclature and 
bibliography to retain as distinct two forms 
which must eventually be united, than it 
will to unite under one name two forms 
which must in the end be separated. 
The whole number of genera which, in 
the acceptation of the writer, are found in 
the region indicated is 1118; the whole 
number of species 3234. These are dis- 
tributed among the large groups, as shown 
in table following. Itis proper to note that 
in this list there is included a relatively 
small number of existing species whose re- 
mains have been found in pleistocene de- 
posits of old lakes and of caves, accom- 
panied by remains of other species either 
now extinct or having a geographical dis- 
tribution different from the present. A 
larger proportional number of such liv- 
ing species is found in the group of birds 
than in any other, there being 33 such 
species. 
