CHAPTER II 



THE BRANCHIOPOUA 



Sub-Class Branchiopoda, Latreille (1817). 



Order 1. Anostraca. 

 „ 2. Notostraca. 

 „ 3. Conchostraca. 

 „ 4. Cladocera. 

 Sub-Order 1. Calyptomera. 

 Tribe 1. Ctenopoda. 

 „ 2. Anomopoda. 

 Sub-Order 2. Gymnomera. 



Tribe 1. Oiiychopoda. 

 ,, 2. Haplopoda. 



Definilioa. — Crustacea in -wbicli the carapace may form a dorsal 

 shield or a bivalve shell or may be entirely absent ; the number of 

 trunlc-somites varies greatly ; the posterior part of the trunk is 

 without lim1)s and usually ends in a caudal f urea ; the antennules 

 are generally reduced and luisegmented ; the mandibles have 

 no palp or only a vestige of one ; the maxillae are reduced or 

 absent ; the trunk-limbs, Avhich vary greatly in number, are 

 generally of uniform structure, rarely pediform, generally foliaceous 

 and lobed ; the position of the genital apertures varies greatly ; 

 the paired eyes are rarely absent; development usually -with 

 metamorphosis ; young hatched in nauplius or metanauplius stage. 



Historical. — The earliest mention of any of the Branchio})oda is 

 found in the works of Swatumerdam, who, in 1G69, described a 

 species of Daphnia as " Pulex aquaticus arborescens," and the name 

 of " water-fleas " has since been commonly applied to the group of 

 Cladocera. Apus and Branchiims were descinbed early in the 

 eighteenth century, and, together with Dajyhnid, formed the sub- 

 jects of a series of remarkable memoirs (1752-1756) by J. C. 

 Schatier. The classical work of 0. V. Muller, Entomosiraca sen 

 Inseda testacea (1785), described a large number of new types and 



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