42 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. 
As we are dealing primarily with the fresh-water species, no 
lengthy description of the group is here necessary. 
The earlier history of our knowledge of the animals of this order is 
given by Baird. According to this authority, the first to mention 
any fresh-water species of this group was Stephan Blankaart,* in his 
Schou burg der Rupsen, Wormen, Ma’ den, en vliegende Diekens tot Amster- 
dam. Leeuwenhoek adds numerous interesting details, and is accredited 
by Hoek with being the first to discover the relation between the 
remarkably diverse stages which occur in the history of the Cyclops. 
However, it is evident that he had a very incomplete knowledge of 
the metamorphoses. 
De Geer gives rather characteristic figures of a Cyclops in Memoires 
pour servir al Histoire des Insectes, vol. vii, 1778. 
Mueller, in his great work on Entomostraca, adds new facts, defines 
species and forms the genus Cyclops. 
Ramdohr, in 1805, gave sundry additions to the knowledge of these 
animals in his Beitrage zur Naturgeschichte einiger Deutschen Monoculus- 
arten. In this work the post-embryonic history is quite fully outlined. 
Jurine, in his classic work Histoire des Monocles qui se trowvent aux 
Environs de Geneve, 1820, crystallized what previous authors as well as 
his own original experiments had brought to light of the anatomy and 
biology of these animals. 
Ferussac (Memoire sur deux novelles especes d’ Entomostraces) re- 
describes known species. 
Gunner, Stroem, and Viviana seem to have had little effect on the 
knowledge of the group, though they wrote prior to Jurine. 
A recent author attempts to revive the names of Jurine, though 
hitherto it has been thought hazardous to attempt a specific identifi- 
cation. 
The German author, C. L. Koch, who only incidentally studied 
this group, distinguished more or less perfectly a variety of species 
which have been reinstated in our literature by Rehberg. Although 
this proceeding seems quite unjust to the careful authors whose de- 
scriptions are recognizable in themselves, the law of priority must 
probably prevail. Koch’s Deutschlands Krustaceen appeared in 1838. 
Baird’s British Entomostraca, without greatly extending our knowl- 
edge of this order, put in readable form and made available to English 
readers what was known, and added interesting facts. He distin- 
guished two families of Copepoda, (1) Cyclopide, (2) Diaptomide. The 
first included the genera (1) Cyclops, (2) Canthocamptus, (3) Arpacticus, 
(4) Alteutha; and the second the genera, (1) Diaptomus, (2) Temora, 
(3) Anomlocera. 
* Latinized Stephanus Blanchardus. Hoek recognized Cyclops brevicaudatus or C, bicuspidatus as the 
ono described, chiefly through knowledge of the present inhabitants of the locality. 
