History of British Entomostraca. 517 



turalists who have written upon this genus ; he only describes the 

 Cypris strigata of Muller. M. Daudebart de Ferussac, fils, in a 

 memoir published in the " Annales du Museum d'HistoireNaturelle, 

 Tom. 7th/' 1806, describes a new species ; and M. Risso, in his" His- 

 toire Naturelle des Crustaces des Environs de Nice," 1816, describes 

 two additional ones ; but though these additions were made to the 

 number of known species, and although Latreille, in Cuvier's "Regne 

 Animal," 1817, and Lamarck, in his " Hist. Nat. des Animaux sans 

 Vertebres," 1818, give a variety of details concerning the genus 

 generally, little real knowledge concerning the anatomy of the in- 

 habitants of the tiny shells was conveyed to us, as Ramdohr's work 

 seems to have attracted no attention, till M. Straus published his 

 admirable paper on the genus Cypris in the 7th Vol. of the " Me- 

 moires du Museum d'Histoire Naturelle," 1821, containing a most 

 elaborate anatomical description of the genus, with a notice and fi- 

 gures of three new species not described by Muller. About the 

 same period as Straus read his paper before the Academy, appeared 

 Jurine's splendid work on the Monoculi, containing many very in- 

 teresting details of this genus generally, with beautiful figures of 

 18 species ; but both of these authors appear to have been ignorant 

 of the previous work of Ramdohr, as we find no reference made by 

 either of them to his excellent little work, though published fifteen 

 years prior to theirs. Desmarest in his " Considerations Generales 

 sur les Crustaces," 1825, although he gives a very good account of 

 the different genera, taken chiefly from Straus and Jurine, with a 

 description of 21 species, takes no notice of Ramdohr ; though M. 

 Latreille, in the last edition of the " Regne Animal," 1829, notices 

 his memoir with all due approbation, and has contributed much to 

 make his labours more generally known. We know of no original 

 memoir upon this genus having been published in this country, — 

 though in " Rees' Cyclopedia," under the Art. Monoculus, we have 

 the species described as given by Fabricius : and in Leach's article 

 Crustacea in the "Edinburgh Encyclopedia," we have no details, 

 and only two or three species taken notice of. 



Anatomy. — Muller, Ramdohr, Jurine and Straus, all differ in 

 many respects in describing the anatomy of the genus Cypris, both 

 as regards the nomenclature and the use of the parts described by 

 them. In minuteness of detail and accuracy of description and 

 figures, the memoir of Straus, however, stands pre-eminent amongst 

 those of his fellow-labourers, and though in the following remarks 

 we shall take all advantage of the memoirs of the other three au- 

 thors, we shall follow M. Straus more particularly, in his nomen- 



