m 



TAGE SKOOSBERO 



'hr names of ihrsr 

 main frotifm. 



untmary of the dif- 

 •rcncef behveen nn/ 

 pinion of the funda- 

 lenlal classification 

 f the recent Ostrn- 

 id.i and that of 

 G. O. Sars and 

 G. W. MiUler. 



1 ilitl uot tliink it convenient to use the nomi'iiclatuic intiiHluccd liy G. 0. Sahs ior 

 these groups. It seems unsuitabU' for tlic following reasons. The names Myoducopa utkI 

 PiKiocopa have been used by preceding writers in different senses; if the name Mijudocupa is 

 retained for the C y p r i d i n i d s or for the H a 1 o c y p r i d s, it would be used in a new 

 sense, differing from both G. 0. Sars' and G. W. MOllkr's view. If we retain the names 

 Myodocopa. Cladocopa, Podocopa and Platycopa it would be impossible to introduce a thoroughly 

 consistent nomenclature. G. 0. S.\RS took these names from the structure of tlie s(>cond 

 antenna in the different groups: Myodocopa refers to the muscular structure of this limb, 

 Hjc')dr,; et xtbmr,. ..the muscular oar"*. Cladocopa refers to the fact that both the e.xopodite and 

 the endopodite are developed as natatory implements, x>.ad&; et vMT.■r^ ,,the branched oar". 

 Podocopa refers to the fact that this limb is developed as a crawling leg, -oSo; et xwtiy, ,,the 

 leg-shaped oar". Platycopa refers to the flatness of the same appendage, Ti/.aTu? et xwtitj, 

 ..the flattened oar". It seems impossible to find a suitable analogous name for C" y p r i d i n i d s 

 and H a 1 o c y p r i d s, as these groups have second antennae of almost quite the same type. 

 It is also to be noted that the term Cladocopa suits one genus among the Halocyprids 

 as well, namely Thaumatocypris. 



For these reasons it seems to me most convenient to give quite new names to these five 

 groups, which, according to G. W. MCller, may be termed sub-orders. I have chosen for them 

 the temis: Cypridiniforrnes, Halocypri formes, Polycopifortnes, Cypriformes and Cytherelliformes. 



The difference between G. 0. Sars', G. W. MCLLER's and my classification is shown in 

 the following table: 



Myodocopa G. \V. MtJLl.i:i! 



Podocopa 



Myodocopa G. (). Sars 

 Cladocopa 



Podocopa ,, ,, ,, 

 Platycopa ,, ,, ,, 



Halocypriformes 

 Cypridini formes 

 Polycopiformes 



Cypriformes 

 Cytherelliformes. 



'he mutual relation.^ 

 of my five main 



groups. 

 Cypridiniforrnes, 

 Halocypriformes 



and 

 Poly cop i formes. 



The question of the nmtual relations between these groups seems to be exceedingly 

 difficult to answer satisfactorily. 



G. W. MCller assumes that Halocypriformes and Polycopiformes 

 are more closely related to each other than they are to Cypridiniforrnes; Polycopi- 

 formes are to be considered as a small branch of the first-mentioned group, a branch 

 that has preserved primitive features in a number of respects. The characters that show 

 the closer relationship of these two groups would be the position of the first antenna high 

 up on the forehead and the unsymmetrical exit of the sexual organs. I think that G. W. 

 Mt'LLER has been somewhat too hasty in this deduction. These two characters, the place 

 of attachment of the first antenna and the way in which the sexual organs open out. 



* G. O. Sars wTites, 1865, p. 10: ,,Den sidste Del af Sammensaetningen, xdnri, Aare, er specielt anvendi 

 paa disse Antenner, da deres Betydning som Bevaegelseorgauer er noget, man vil finde mere eller mindre tydeligt udpraeget 

 gaai' igjeiinem den hele store Krebsdyrafdeling, Entomostraca. (The last part of the compound, y.cj.^ij. oar, is specially 

 used for these antennae, as their importance as locomotory f)reans will lie found nioic or less riunknl throughout Ihr 

 whole ^Teat Crustacean group Entomostraca.) 



