DAPHNIADiE. 
65 
as his B. sima, but which Straus says is not so, but is his 
B. macrocopus. The figures which Joblot gives are very 
indifferent, and it is not easy to say what species they are 
meant to represent. 
Schceffer, in his Memoir ‘ Die griinen Arm -Polypen die 
geschwanzten und ungeschwanzten zackiger Wasserflohe/ 
1755, describes at great length two or three species, under 
the name of Geschwanzten zackiger Wasserjtoh , and Un- 
geschwanzten zackiger Wasserjtoh , or water-Jlea with a tail , 
and water-Jlea without a tail ; and this memoir is the first 
in which an attempt is made to distinguish different 
species, — the various authors whom I have quoted above, 
having all, with perhaps the exception of Joblot, described 
only one and the same. He figures two species, the 
B. pulex and sima , and gives a sketch of the head only of 
a third, which, being provided with a tail, has been quoted 
by Muller and Straus as the B. longispina. This memoir 
contains a great deal of very interesting information with 
regard to these little creatures, and having been partly 
translated into French by Jurine, at the end of his work 
on the Monoculi, it has become more available to the 
naturalist. In his ‘ leones Insectorum circa Ratisboniam 
indiginorum/ 1766, the* same author figures the B. pulex 
under the name of “ Branchipus conchiformis primus,” 
and in his ‘ Elementa Entomologica/ published in the 
same year, I believe, he again figures it under the name of 
“ Branchipus conchiformis.” 
Poda, in his ‘ Insecta Musaei Graecensis,’ 1761, de- 
scribes shortly the same species, under Linnaeus’s name, 
Monoculus pulex , andLedermliller, in his ‘Mikroskopischen 
Gemuths und Augen-ergotzung,’ 1763, gives an in- 
different figure of a species, which however is easily 
recognisable as the same. 
Geoffroy, in his 6 Hist, abreg. des Insectes/ 1764, 
gives a good many details of this genus generally, and 
describes a species under the name of “ Perroquet d’eau,” 
which Muller quotes as his quadrangula , but which Straus, 
I think more correctly, considers the pulex. 
5 
