Suboi'do IL 



PHYLLOPODA. 



Character. Branchiopoder af meget forskjellig 

 Kropsform, dels uden, dels med Rygskjold, det sidste 

 undertiden irdviklet i Form af 2 voluminose, det 

 hele T>yT omsluttende Valvler. Legemets Segmenta- 

 tion forskjellig hos de forskjellige Former. Øinene dels 

 stilkede, dels sessile, undertiden næsten sammensmel- 

 tede; et mediant Enkeltoie ^ocellus) tilstede. Følerne 

 i Regelen meget ulige xrdviklede; Iste Par som oftest 

 meget smaa og udelukkende sensitive; 2det Par 

 af forskjellig Bygning, snart rudimentære (hos det 

 voxne I>yr), snart udviklede til kraftige 2grenede 

 Aarer, eller til tangformige Griberedskaber (hos 

 Hannen). Ovorla^bcn v(d udviklet, klajiformig; Under- 

 læl)en i Regelen manglende. Kindbakkeinc hos det 

 udviklede Dyr uden Palpe. To Par Kjæver tilstede, 

 begge smaa og af foi'holdsvis sim])el J>ygiiing Alle 

 bag Munddelene følgende Lemmer respiratorisko, af 

 tilnærmelsesvis uniform Bygning og bladdannet lap- 

 p(!t Form; deres Tal meget forskjelligt, undertiden 

 abnormt stort. Udviklingen i Regelen en eompli- 

 ceret Metamorphose, begyndende med et fritNau])lius- 

 Stadium. Lidlandsdyr. 



Bemærkninger. Denne Underorden omfatter et 

 ikke meget stort Antal Dyreformer, der imidlertid 

 viser meget væsentlige Forskjelligheder, saavel hvad 

 det ydre Udseende som den indre B^'gning angaar. 

 Hvad der hovedsageligt characteriserer denne Af- 

 deling af Branchiopoder, og har givet dem sit Navn, 

 er Structuren af de bag Munddelene følgende Lem- 

 mer, der alle viser et lignende bladformigt og lappet 

 Udseende som de til Midtkroj)pen hos Phyllocariderne 

 horende saakaldte Branchialfodder. Da de tillige i 

 sin Function er udpræget respiratoriske, benævnes 



Sudordo II. 



PHYLLOPODA. 



Characters. Bi-anchiopods of very various 

 shape, partly without and partly with carapace, 

 the lastnamed sometimes developed in the form of 

 2 voluminous valves enveloping the entire animal. 

 The segmentation of the body different in the 

 various forms. Eyes partly pedunculated, partly 

 sessile, sometimes nearly' coalescent; a median single 

 eye (ocellus) present. Antenuæ, as a rule, very 

 unequally developed; 1st pair most frequently very 

 small and exclusively sensitory; 2nd pair of vari- 

 able structure, sometimes rudinientar}^ (in the adult 

 animal), sometimes developed to powerful, 2-branched 

 oars, or to pincer-sha])ed prehensile apparatus (in 

 the male). Anterior lip well developed, tlap-formed; 

 posterior lip, as a rule, wanting. Mandibles, in the 

 developed animal devoid of palpi. Two ])airs of max- 

 illæ present, both small and of relatively simple 

 structure. All tlie ap])endages placed behind the 

 oral ])arts respiratory, of approximately uniform 

 structure and leaf-formed shape ; their number very 

 variable, sometimes abnormally large. The de- 

 velopment usually a complicated metamorphosis, 

 commencing with a free Xauplius-stage. Inland 

 animals. 



Remarks. This sub-order includes a not very 

 large number of animal forms, which exhibit, how- 

 ever, very material divergencies, both in respect of 

 the external appearance as well as in the internal 

 structure. Wliat chietly characterizes this division of 

 Branchiopods and lias gevin.to it its designation is, 

 the structure of the a])pendages placed behind the 

 oral parts, whidi all exhibit a similar leaf-sjiaped 

 and lobed ajijiearance as the so-called branchial-feet 

 pertaining to the mesosome in the Pliyllocarida. 

 As tiiey are, besides, in their function ])rominently 



