42 



Ved Basis al' dette ligesom. de 3 følgende Fodpar er 

 fæstet 2 vel udviklede Gjeller, og foran dem danner Rod- 

 leddet et knudeformigt, med et Bundt af lange, bugtede 

 Børster besat Fremspring. 



2det Fodpar (Fig. 19) er af samme Størrelse og Byg- 

 ning som Iste Par og skiller sig kun ved et noget af/igende 

 Langdeforhold mellem 3die og 4de Led samt derved, at 

 Saxenes Fingre er noget længere. 



odie Fodpar (Fig. 20) er af meget spinkel Bygning 

 og stærkt forlænget, omtrent af bele Forkrojipens Længde. 

 3die Led er lidt kortere end 4de og begge langs sin indre 

 Kant bevæbnede med en enkelt Rad af spidse Torner for- 

 uden fine Børster. Sidste Led er stærkt forlænget os tyndt. 

 noget afsmalnende mod Enden og forsynet med spredte 

 Borsteknipper. Endekloen er omtrent balvt saa lang, lefor- 

 mig sammentrykt og langs sin indre Kant besat med fine 

 Torner. Svømmegrenen er fuldkommen af samme Udseende 

 som paa de 2 foregaaende Par, og heller ikke det knude- 

 formige borstebærende Fremspring ved Basis mangler. 



4de Fodpar skiller sig i ingen Henseende fra fore- 

 gaaende Par. 



Derimod viser sidste Fodpar (Fig. 21) tydeligt ucl- 

 prægede Afvigelser. Det er omtrent af samme Længde 

 som de 2 foregaaende Par, men mindre stærkt afsmalnende 

 mod Enden og viser et noget forskjelligt Længdeforbold af 

 de enkelte Led. 3die Led er saaledes ber adskilligt længere 

 end 4de, og mangler ganske Torner, hvorimod Børsterne i 

 den indre Kant er længere og talrigere. Ogsaa 5te Led 

 er forholdsvis storre end paa de foregaaende Par og neppe 

 kortere end 4de. Endelig er sidste Led af fuldkommen 

 lineær Form, overalt af ens Brede og i begge Kanter, men 

 navnlig i den indre tæt besat med korte, kostformige Borste- 

 knipper. Endekloen er ganske rudimentær, afstumpet i 

 Spidsen og oftest ganske skjult mellem de fra foregaaende 

 Led udgaaende Børster. 



Gjellerne (se Fig. 22) viser den sædvanlige pyramidale 

 Form og bladede Bygning, men udmærker sig ved sit be- 

 tydelige Antal. Man tæller paa hver Side 10 saadanne, 

 medregnet den ovenfor omtalte supplementære Gjelle paa 

 sidste Par Kjævefødder. Naar undtages denne sidste og 

 den allerbageste ise Fig. 21), som begge er uparrede, er 

 de øvrige ordnede i en dobbelt Række, saaledes. at til hver 

 Fod svarer 2 Gjeller (se Fig. 17 og 19). 



Bagkroppens Svømmevedbæng (Fig. 23 og 24) er 

 kraftigt udviklede og bestaar af en tykkere, muskuløs og 

 noget fladtrykt Basaldel og 2 med talrige cilierede Rand- 

 børster besatte, smalt lancetformige Grene eller Endeplader. 

 Af disse sidste er den indre noget kortere end den ydre 

 og ved Roden i den indre Kant forsynet med et forholds vist 

 temmelig stort cylindriskt eller noget kolleformigt Appendix 

 (se Fig. 24). Iste Par skiller sig dog i denne Henseende 



At the base of this pair of legs, as also of the three 

 succeeding pairs, are attached 2 well-developed branehiæ. 

 and, anterior to the latter, the basal joint forms a tuberculi- 

 form projection. furnished with a buncb of long, curving 

 bristles. 



The 2nd pair of legs (fig. 19) are similar in size 

 and structure to the Ist. being distinguisbed from them 

 merely by a somewhat different proportion in length between 

 the 3rd and 4th joints, as also by the fingers of the chela 

 being a trille longer. 



The 3rd pair of legs (fig. 20) are very feeble in struc- 

 ture, and greatly produced, their length about equalling that 

 of the whole anterior division of the body. The 3rd joint is 

 a trille shorter than the 4th. and both exhibit along the 

 inner margin a single series of sharp-pointed spines. ex- 

 clusive of slender bristles. The last joint is greatly pro- 

 duced, and slender. tapering a little toward the extremitv. 

 and provided with scattered fascicles of bristles. The 

 terminal claw is about half as long. falciform, and beset 

 along the inner margin with delicate spines. The natatory 

 branch has precisely the same appearance as that on the 

 two preceding pairs, and not even is the bristle-beset. 

 tuberculiform 2Jrojection at the base wanting. 



The 4th pair of legs are in no respect distinguished 

 from the preceding pairs. 



On the other band, the last pair of legs (fig. 21) ex- 

 hibit distinct deviations. They are about of the same length 

 as the two preceding pairs, but taper less abruptly toward 

 the end, as also the proportion in length between the 

 different joints is somewhat different. Thus, the 3rd joint 

 is considerably longer than the 4th. and entirely without 

 spines. whereas the bristles on the inner margin are longer 

 and more numerous. The 5th joint, too. is comparatively 

 larger than in the preceding pair, and very little, if at all. 

 shorter than the 4th. Finally. the last joint is perfectlv 

 linear in form. everywhere of the same breadth. and along 

 both margins, but especially the inner. beset with short. 

 scopiform fascicles of bristles. The terminal claw is quite 

 rudimentary, obtuse at the end, and. as a general rule, 

 entirely concealed among the bristles of the preceding 

 joints. 



The branehiæ (see fig. 22) exhibit the usual pyramidr 

 ical form aud lamellar structure, but are characterizcd by 

 their considerable number. On eitber side occur 10. in- 

 cluding the supplementary branchia mentioned above as 

 found on the last pair of maxillipeds. If we except this 

 and the hindmost branchia (see fig. 21), both of which are 

 odd ones, the rest occur in a double series, so that each 

 leg has 2 branehiæ (see figs. 17 and 19). 



The natatory appendages of the abdomen (figs 23. 24) 

 are powerfully developed. and consist of a thickish, muscular. 

 and somewhat flattened basal part, along with 2 slender, lan- 

 ceolate branches. or terminal plates, beset with numerous 

 eiliated marginal bristles. Of these branches. the inner is some- 

 what shorter than the outer. and at the base furnished on the 

 inner margin with a comparatively large, cylindric. or some- 

 what claviform, appendix (see fig. 24). The Ist pair are 



