CYCL0PID.E. 
185 
time,* with the exception of detached notices, such as I 
have mentioned above, one species only of this family 
seems to have been noticed by authors, which, like all 
the other Entomostraca then known, was arranged and 
described under the general name Monoculus. He was 
the first, as I have already mentioned, to divide the dif- 
ferent animals which figured under this name into dis- 
tinct genera ; and having discovered in the marshes and 
on the shores of Denmark and Norway, a variety of 
species, all agreeing in many characters with each other, 
he formed them into one distinct genus, and gave the 
name of Cyclops to it. He has given a number of inter- 
esting particulars of many of these little creatures, but 
has fallen into two or three mistakes concerning them, 
which will be pointed out hereafter. 
Some time after Muller, Ramdohr, in 1805, published, 
in his little work on the Monoculi, f a very correct account 
of the anatomy, &c. of three species found in fresh water, 
accompanied with plates, which possess very considerable 
accuracy, and traces their whole transformation from the 
egg to the perfect animal. 
Louis Jurine J (pere) some years afterwards published 
his excellent monograph, and in it has given us the fullest, 
most interesting, and most accurate information upon the 
fresh- water species belonging to the family, of any author 
who has written upon the subject. He declines the name 
of Cyclops, which Muller had given it, and prefers the old 
term Monoculus ; but he has rectified the mistakes which 
that naturalist had fallen into, and completed, by a series 
of wonderfully careful experiments, the previous discoveries 
of Leeuwenhoek and De Geer. This he had done, with- 
out even alluding to the labours of Ramdohr, and indeed 
* “ Unicum quidem ante annum 1769, quo in Synopsi Monoculorum quatuor 
novas Cyclopes fluviatiles publici juris feci, nempe Monoculus quadricornis 
Entomologis innotuit.” — Entomost., 100. 
f Beytrage zur Naturgeschichte einiger deutschen Monoculus-arten. 4to, 
Halle, 1805. 
t Histoire des Monocles qui se trouvent aux Environs de Geneve, 1820. 
