73 



er utydeligt tredelt <)<j; har i den iudrt; Kant en lin 

 Ciliering (Fig. 9). 



Bag Kiiidbakkerne folger nu tæt sammen de 

 øvrige Munddele (se Tab. XII, Fig. 1), som det ikke 

 er saa ganske let at isolere, da de delvis er for- 

 bundne ved et Sy.stem af stærke ('liitinlister. imid- 

 lertid er det ikke saa vanskeligt at paavise, at de 

 danner 'd paa hinanden folgende Rækker: forrest en 

 vel udviklet Underlæbe, deretter 2 Par ucirmalt ud- 

 viklede Kjtever. 



Underlæben (Fig. 10, 1, Fig, 11) hestaar af 2 

 symetriske Halvdele eller Lappe, forbundne i Midten 

 ved en tynd Membran. Fnliver .Sidela]i er stottet 

 af en noget bueformig ("liitinplade, der ved Basis 

 liænger sammen med ilen tilsvareu<l(' forreste Kjæve 

 (se Fig. 1()\ og hvis Ende danner en smalt afrundet 

 indboiet Jjob besat med tætte Haar. Indad fort- 

 sætter < 'hitinpladen sig i en tymlen', halvt mem- 

 branos liamelle, der ligeledes er tint iiaaret i den 

 indre Kant ng længere l)agtil har et tæt tværstribet 

 marginalt Parti. Af andre Forskere er Underlæbens 

 Sidelappe tydede som Iste Kjævepar, hvad der 

 aabenbart er urigtigt, da disse Lappe er fuhlstændig 

 ubevægelige og desuden forbundne i Jlidten ved en 

 tydelig ^lembran. Mærkelig er iethvertfald hos nær- 

 værende (Trn])pe Tilstedeværelsen af en vel udviklet 

 Underlæbe, som hos de høiere Crustaeeer. Thi hos 

 andre Phyllopoder, ligesom ogsaa hos den store Fler- 

 lied af Entomostraceer, sees neppe Jen Antydning til 

 denne Del. 



Iste Par Kjæver (Fig. 10 m'. Fig. 12) danner 

 hver en i Enden oxeformigt udvidet Chitinplade, der 

 med sin tilspidsede Basis er forbunden med Under- 

 læbens Chitin.skelet, og derfor ved Dissection ial- 

 mindelighed faaes i Sammenhæng med Underlæben. 

 Paa (Irnnd af Chitinstibstantsens Elastieitet kan de 

 imidlertid til en vis (Trad bevæges inind hinanden, 

 og en Did tydidige Muskler, der lober skraat indad, 

 besørger denne enkle Bevægelse. 1'aa den oxe- 

 formigt udvidede iiiilii' 1'hide er de bevælmede med 

 talrige korti' Pigge og en hel Del stive Børster. 

 Det forreste Hjdrne danner en særskilt, noget paa- 

 tvæi't stillet liMp, s(im ei' fors\-net me(l en Del noget 

 sta^rkere Pigge. 



'idet Par Kjan-ei' 0'"ig'- 1, "i "'. Fig. lo), der af 

 andre Forskere (Packai'd) feilagtigt er tydede som 

 et Slags K ja>vefodder, er af mere membranos Be- 

 skatfenlied (jg ender indad med en afrundet, tunge- 

 formig Tyggelap, besat med talrige grovt eilierede 

 Børster. Paa den ydre Side lindes en stumpt coni.sk 

 Udvidning a f en noget lignende spongios Jieskatfen- 

 hed som Fixldenies Epipoditer. Denne U<lvidning 

 maa na'rmest ojifattes som et Slags rudimentær 

 Palpe. 



Fo(l(lerne er, som (ivenfnr nævnt, overordentlig 

 talrige, idet der paa den bagre Del af Truncus 

 (Metasome) tindes nu^nge flei-e Fodpar end der er 



10 — Q. O. Sårs; Fauna Xurvt-fiix. 



The innermost tooth is faintly tripartite, and is 

 tinely ciliated on its inner edge (tig. 9). 



The remainiler "f the oral parts now follow 

 (dosely beliiiid the mandibles (see PI. XII, tig. 1), 

 and ai'e not very easy to separate from one ano- 

 ther, being jiartially connected by a .system of 

 .strong chitinous tillets. It is not, however, difficult 

 to see that they form 3 consecutive series: in front, 

 a well-developed inferior lip, and then 2 jiairs of 

 normally-developed maxillæ.. 



The inferior lip (tigs. 10.1, 11) consists of 2 sym- 

 metrical halves or lobes, connected in the middle 

 by a thin membrane. Eacii lobe is supported by a 

 somewhat arched chitinous lamella which is united 

 at the base to the corresponding anterior maxilla 

 (see fig. 10), and whose end forms a narrowly 

 rounded, incurved, thickly ciliated lobe. The chiti- 

 nous lamella is continued inwards in the form of a 

 thinner, half-membranous lamina also finely ciliated 

 on the inner edge, and whose marginal part, farther 

 back, is thii'kly barred transverseh-. Tiie lateral 

 lobes of the lower lip are designated b\- other na- 

 turalists as the first ])a\v of maxillæ, Imt this is 

 clearly incorrect, as these lobes are (|uite immo- 

 vable, and are connected in the middle liy a distinct 

 membrane. The ))rcscnce. in this group, of a well- 

 I developed inferior lip. as in tiie higher Crustacea 

 I is, at all events, remarkable; for in other Phyllo- 

 poda. as also in the majority of Entomostraca, there 

 is scarcely an indication of this part. 



Each of the first pair of maxillæ (figs. 10 m', fig. 

 [ 12) has the form of a securiformly ex])anded ciiitinous 

 lamella, which is connected by its pointed i)ase with 

 the chitine skeleton of the inferior lip. and is there- 

 fore, when dissected, generally detached in conjunc- 

 tion with that part. On account of the elasticity of 

 the chitine however, they can, to a certain extent, be 

 moved towai'ds one another, and several distinct 

 muscles, rnnning oi)li([uely inwards, elfect tJiis simple 

 movement. <)n th(> securiformly expanded inner end, 

 the maxilla' are armed with numerous short spines, 

 and a number of stiff iiristles. The foremost corner 

 is in the t'orm of a peculiar, somewhat oblii|aely- 

 placed lobe, furnished with a few stronger spines. 



The second pair of maxillæ (fig. 1 m -, fig. 13) 

 which have been incorrectly interpreted by other 

 naturalists (Packard) as a sort of maxillii)ed. are of 

 a more membranous nature, and terminate inside 

 with a rounded linguiltuni masticatory lobe, clothed 

 with numerous c'oarscly ciliated Iiristles. On the 

 outer side, there is a bluntly conical expansion 

 of a spougv nature, somewhat similar to that of 

 the ejiipodites of the legs. This ex])ansion should 

 probablv be regarded as a sort of rudimentary palji. 

 The legs, as stated aI)ove, are remarkably 

 numerous, there Ijeing on the posterior part of the 

 trunk (the metasome), many more jiairs of legs 



