258 BRITISH ENTOMOSTRACA. 



as consisting of two kinds, differing either in sex or 

 species, the one having two antennae longer than Hie body, 

 and the other having none. Strom again, in the ' Skrifter 

 Kiobenhavnske Selskab,' 1770, describes and figures an- 

 other species, and evidently a second time mistakes the 

 tail for the head. 



In describing the Argulus, I have mentioned that 

 Linnaeus, in his twelfth edition of the ' Syst. Nat.,' con- 

 founded that animal with the Caligus. In the 'Fauna 

 Suecica' he described them as separate species ; but in 

 this latter work he not only quotes his own previous de- 

 scription of the Argulus as a synonym for the Caligus, 

 but he even refers to Loefling's figure of that animal as 



O O 



further evidence of their identity. This erroneous syno- 

 nymy is repeated by Fabricius, in his ' Sy sterna Entomo- 

 logiae,' 1775, and by Gmelin, in his edition of the ' Systema 

 Nature,' 1788. Slabber, however, previous to Gmelin's 

 edition, in his ' Naturkundige vciiustigingen,' 1778, had 

 given a figure, under the name of Oniscns lutosus, of a 

 species belonging to this family, and delineated the true 

 antenna? and some other parts very correctly. 



0. Fabricius and Herbst seem also to have better 

 understood the anatomy of the animals belonging to this 

 group. The species which they have described, the former 

 in the ' Fauna Grcenlandica,' 1780, and the latter in the 

 'Berlin Gesellschaft Skrifter,' 1780 and 1782, are accom- 

 panied, especially the latter, with a number of details, and 

 arc pretty accurately described by both. Miiller, in his 

 ' Prodrom. Zoologia? Danicre,' 1776, introduces the genus 

 under the name of " Binoculus," adopting that name 

 from Geoffrey ; but in his ' Entomostraca/ 1 785, he founds 

 the genus Caligus. Hitherto no zoologist had clearly 

 ascertained the situation of the eyes, and it was from this 

 apparent blindness that the generic name \\as suggested 

 to him. With regard to their exact situation, however 

 e\en lie Avas decei\ed, for though he really saw the true 

 eyes, he. yet did not consider them to be such, but 

 absolutely mistook a dill'erent. part altogether \ot\vith- 



