I I BRITISH ENTOMOSTRACA. 



Linna-us, in the tenth edition of his ' Systema Naturae,' 

 1758, and again in his 'Fauna Suecica,' 2d edit. 1761. 

 notices the Argulus under the name of J\Io)iocult(sfo/i<ic<>//x, 

 In the 12th edition of the 'Systema/ 1707, he unfor- 

 tunately, however, confounds it with the Caligus, under the 

 name of Monocuhis piscinus. Under this name he refers 

 to the Argulus, as described by himself, in his two last- 

 mentioned works, and by Loefling ; to the Caligus, as 

 described by Master, in his ' Opuscula Subseciva / and to 

 the Prosopistoma, figured by Geoffrey, in his ' Insectes de 

 Paris.' Fabricius, in his ' Systema Entomologist/ 1775, 

 and Gmelin, in the 13th edition of the ' Systema Natune.' 

 repeat this error, giving the species ~M<>,i<><-tilitx /y/.vr/'/^/.v, 

 with all the faulty svnonvma. Geoffrov, in his ' Insectes 



/'*/ */ ' 



de Paris/ 1702, observing that this, and some other 

 species of Entomostraca, had two eyes, formed the genus 

 Binoculus to receive them. This little parasite he had 

 once found upon the stickleback ; but not having time to 

 examine it attentively, he has given no lengthened de- 

 scription, merely noticing it under the name of Binocnln* 

 yastcrostei."* 



Ledermiiller, in his 'Amusements microscopiques/ 

 ])art i, 1764, has given a figure of the Argulus, and de- 

 scribes it as "a small aquatic insect," which he thought 

 worthy of attentive consideration. His figure is enor- 

 mously magnified, and very indifferent. Midler is the 

 first author who has given it the name of Argulus. In 

 his ' Entomostraca/ 1785, he established the genus 

 Argulus, and described two species, indicating, besides, a 

 third. The last is a very doubtful species, while the two 

 first are the same, the only diflerencc being in age, 

 Miiller erroneously considering the young animal as dis- 

 tinct from the adult. 



' The second species of his genus jlinor-iilus lie calls 7>Y//wW//.v 1m mi- 

 K)ilii/-i-i<-tts, .-mil i.'-ixo ;ts Mmnmns (lie rd'crciiccs of Frisoh, Loefling, and 

 LiniKms i loth edit.), to the ijriiiis Arjrulus. Aii examination <>f the liirmv 



arromjiain MILT Ilir description distinctly shou-.. lin\\c\cr, that this i., a totally 



different animal, lu-injj the 1 Prosopistoma of Lai rrille. 



