498 ‘REVIEWS AND BOOK NOTICES. 
chapter (pp. 1-70), embrace all the Ortalide at present known 
from all parts of the world. The existing literature of the Orta 
lide is also fully reviewed.. The number of the North American — 
species of this family described in the body of the work is sixty- 
six. 
The North American Trypetide have been the subject of a 3 
monograph which appeared in the first volume of the same serios 
(1860). The additions to this family, received by Mr. Loew since 
that publication, were so numerous that he thought it worth while 
to return to the same subject again. The present work contains 
the descriptions of sixty-one North American Trypetidæ, thirty- 
eight of which were not contained in his first monograph. To ui 
are added twelve South American species, for the sake of com- ; 
parison with closely allied North American ones. tna 
To the volume are added four plates, with 116 figures, Tepr* . 
senting the wings of nearly all the described species. : 
The translation of the volume from the German. manuscript was l 
made by Baron R. Osten Sacken. The four volumes of the A0 
ographs, etc., hitherto published, contain the following families of l 
Diptera: Large monographs ; Dolichopodidæ (Vol. II), Tipu 
brevipalpi (Vol. 1V), Ortalidæ (Vol. III), Trypetidæ (Vols. : 
IIT). Smaller monographs (all in Vol. I): Sciomyzide, sh 
dridæ, Cecidomyidæ. 
Tue UNICELLULAR Nature OF THE Ixrusorra.* — Anything 
‘that comes from the pen of the distinguished profes I 
striking and original. The main idea of the present paper Br 
reaffirmation of the unicellular nature of the Infusoria, cil 
tinctly enunciated by Von Siebold in 1845, when he Hedel 
Ehrenberg’s well known conceptions of their organization. © 
divides the animal kingdom into two groups, the on". 
Protozoa, and the many-celled or: Metazoa, and accompa ae 
views with the inevitable phylogenetic table of the animal £! 
m. 
This view scarcely seems in accordance wi 
garding the structure of these so-called unicellular infusori 
the reader will turn to that remarkable book, “ Mind and , 
(p. 43) by the late Professor H. J. Clark, he will find the 
th known facts 
* Zur Morphologie der Infusorien; von Ernst Heckel. From the Jon g i 
Bd. vii. Leipzig, 1873. 8vo, pp. 54, with two plates. . oe 
