192 PITH OF THE PERIODICALS. 



describing the young, but not tracing them to their final state, 

 which Rhamdohr and Jurine have since done. Leeuwenhoek, 

 Swammerdam, and Schasflfer, give some details respecting these 

 insects ; but it is to Miiller we are chiefly indebted. He col- 

 lected in one memoir, and arranged into genera and species, not 

 only those previously known, but added a number of new 

 species found in the fresh waters of Denmark and Norway, and 

 gave many important and interesting details respecting them. 

 Although Miiller has subsequently been detected in some errors, 

 his work, published in 1785, is a most interesting and valuable 

 memoir. The memoirs of Straus, on Daphnia and Cypris, are 

 exceedingly perfect, and Jurine (fils), Daudebart de Ferussac 

 (fils), Adolpe-Brogniard, Hermann (fils), and Prevost, Milne, 

 Edwards, and Andouin, have each further extended our know- 

 ledge of these animals. 



With the exception of Dr. Leach, British naturalists have 

 done little for the Entomostraca : this author, in the Edinburgh 

 Encyclopaedia, enumerates sixteen British species. Samouelle 

 increases these to twenty, and at about this number the cata- 

 logue remains at the present period. 



The natural arrangement of Entomostraca has been dis- 

 puted by naturalists. Desmarest gives a view of all arrange- 

 ments of them, previous to his own. Latreille, in his " Cours 

 d'Entomologie," gives the following arrangement of Crustacea 

 generally: — 



( Malacostraca.) 



First Division — Crustacea Maxillosa. 



First Order , Decapoda. 



Second xStomapoda. 



Third Lcemodipoda. 



Fourth Amphipoda. 



Fifth Isopoda. 



Sixth DlCLAPODA. 



(Entomostraca.) 



Seventh Lophyropa. 



Eighth Ostrapoda. 



Ninth Phyllopa. 



Tenth Trilobites. 



Second Division — Crustacea Edentata. 



Eleventh Xiphosuua. 



Twelfth Siphonostoma. 



