SYSTEMATIC AERANGEMEINT. 



The systematic arrangement of the Crnstacea has been 

 a matter of considerable discussion amongst naturahsts. 



Desmarest, in his work,* has given a series of tabular 

 views of the various arrangements which different authors 

 have suggested, from Linna3us to his own time. For a 

 complete view of these we refer the reader to him, and 

 shall only notice a few of the more prominent here, as far 

 as the Entomostraca are concerned. 



Linnaeus places the Crustacea in the class Insecta, 

 order Aptera, and refers all the species of Entomostraca 

 then known, with the exception of two, to one genus, 

 which he calls Monoculus. Fabricius also places the 

 Crustacea amongst the Insecta; the genus Monoculus, 

 embracing most of the Entomostraca, being placed in 

 his Class viii, Polygonata, and the genus Limulus in the 

 ixth, Kleistognatha.f 



Mliller, following his predecessors in arranging the 

 Crustacea amongst the Insecta, places of course the Ento- 

 mostraca in that class also.| He divides them into 

 two great sections, according to the number of eyes, viz. 

 Monoculi and Binoculi. These he subdivides again into 

 Univalves, Bivalves, and Crustacei, according to the form 

 of the shell or covering in which the animal is inclosed. 



Latreille^, andCuvier, || in their first published Methods, 

 also placed the Crustacea amongst the Insecta, the former 

 adopting the arrangement of Miiller with regard to the 

 Entomostraca, and dividing them into two families, the 



* Cousid. geu. sur les Crustaces, 1S25. 



f Systema Eutomolog-ia;, 1775 ; Eutomologia Systematica, 1793. 



X Entomostraca, 1785. 



§ Precis dcs Caractercs gen. des luscctcs, 1796. 



il Tableau element, de I'Hist. Nat. dcs Animau.x, 179S. 



