134 



er særdeles bevægeligt forbundne med hinanden ved en 

 ganske tynd Stilk, saa at del sidste kau slaaes ind mod 

 del første. Endekloen er særdeles liden, stiletformig og 

 næsten ganske skjult mellem de fra sidste Led udgaaende 

 Fjærbørster (sr Fig. 19). 



Brystposen var hos ingen af de erholdte Exemplarer 

 fuldt udviklet; men de 4 Par Plader, der bidrager til dennes 

 Dannelse, var paa de fleste tydeligt anlagte i Form af smaa 

 fra Basis af de 4 første Fodpar udgaaende Lapper (se Fiii. 

 2 Og 3). • 



Bagkroppens Operculum (se Fig. 2 og ::) er særdeles 

 stort og hvælvet, indtagende Størsteparten af Bagkropsseg- 

 mentets Underside. Det viser langs ad Midten en stump 

 Kjøl. der i den ydre Del spalter sig i 2 divergerende Grene. 

 Kanterne er ganske glatte. 



De under Operculet liggende Buglemmer ei- alle ægte 

 respiratoriske og af en særdeles blød og tander Structur. 

 Det Iste Par (Fig. 20) er tydelig tvegrenet, med den indre 

 Gren dannende en bred afrundet i 2 utydelige Segmenter 

 afdelt Plade. den ydre ganske smal. cylindrisk og noget 

 krummet samt bestaaende af 2 tydelige i sin ydre Kant fint 

 cilierede Led. Di øvrige Par synes kun at danne enkle. 

 uregelmæssigt foldede Plader (Fig. 21). 



Halevedhængene (Fig. 22). der træder frem til hver 

 Side af den stumpe Fremragning, som Bagkropssegmentet 

 danner bagtil i Midten, er særdeles smaa. men tydeligt 

 t\ egrenede. med den indre Gren omtrent af Basaldelens 

 Længde, den ydre betydelig mindre. Begge Grene er af 

 lineær Funn og forsynede med nogle meget smaa og fine 

 Børster. 



Hannerne skiller sig ikke i sit ydre meget væsentligt 

 fra Huunerne. unn kjendes dog let ved Iste Par Føleres 

 stærkere Ddvikling og ved den eiendommelige Bygning af 

 Bagkroppens < )perculum. 



Iste Par Folere (Fig. 2.3) er kjendeligt længere end 

 hos Hunnen, hvilket skyldes den langt stærkere Udvikling 

 af Svøben, iler er forholdsvis mere end dobbelt saa lang 

 og sammensat af et særdeles stort Antal af Led. 



Bagkroppens Operkulum (se Fig. 24) ei', som hos de 

 til foregaaende Familie horende Former delt i 4 særskilte 

 Plader. 2 ganske smale i Midten og 2 bredere Sideplader. 

 De mediane Plader, der ligger i umiddelbar Oontact med 

 hinanden. er a f lineær Form og ender hver med 2 tri- 

 angulære Spidser. Sidepladerne er af halvoval Form og 

 paa den ydre Side jevnt hvælvede. Paa den indre Side 

 (si> Fig. 25) tindes nær Enden et eiendommeligt krogformet 

 Appendix, der ved Roden bagtil viser en liden afrundet 

 Lap. Dette Appendix kan bevæges ved særegne Muskler. 

 «lei tydelig! sees at convergere mod Basis af samme. At 

 vi her har at gjøre med Hjadperedskaber ved ( 'opulationen 

 er vel utvivlsomt : dog er det endnu ikke med Sikkerhed 

 oplyst, hvorledes disse Dele herunder fungerer. 



in si/.c has a regular elliptic shape. Both articulations 

 are verv movably connected by an exceedingly narrow 

 stem. which admits of the latter being jerked back toward 

 the former. The terminal claw is verv small, styliform, 

 and well-nigh wholly concealed amidst the plumous bristles 

 (sec fig. 19) issuing from the last articulation. 



The marsupium did not in anv of the specimens col- 

 lected occur fully developed; hut the 4 pairs of plates that 

 contribute to its formation were on most however distinctly 

 indicated in the form of small lobes, proceeding from the 

 base of the 4 first pairs of legs (see figs. 2. 3). 



The operculum of the abdomen (see figs. 2. 3) is ex- 

 ceedingly large and arcuate. occupying the greater part of 

 the under surface of the abdominal segment. It exhibits 

 along the middle an obtuse carina, which. in its outerpart, 

 divides into 2 diverging branches. The edges are quite smooth. 



The abdominal limbs, placed underneath the operculum, 

 are all true respiratory organs, exceedingly soft and deli- 

 cate in structure. The Ist pair (fig. 20) are distinctly bi- 

 ramous, with the inner branch forming a broad, rounded 

 plate, eonsisting of 2 indistinctly defined segments: the 

 outer is quite narrow. cvlindric. and somewhat curved, 

 composed of 2 distinct articulations. ciliated along the outer 

 margin. The remaining pairs would appearto fonn mereh 

 simple, irregular-folded plates (fi'j;. 2] i. 



The caudal appendages (fig. 22), jutting forth on either 

 side of the obtuse projection formed in the middle. pos- 

 teriorly, by the abdominal segment, are exceedingly small, 

 hut distinctly biramous, with the inner branch about of the 

 same length as the basal part. the outer considerably shorter. 

 Both branches are linear in form. and provided with a few 

 exceedingly small and delicate brist les. 



The males do not differ essentiably in their outer 

 habitus from the females, hut are nevertheless easily rec- 

 ognized by the fuller development characterizing the Ist 

 pair of antenna', as also by the peculiar structure of the 

 abdominal operculum. 



The Ist pair of antenna' (fig. 33) are appreciably 

 longer than in the female, a character arising from the 

 much fuller development of the flagellum, which is rela- 

 tively more than double the length. and composed of a 

 very large number of articulations. 



The operculum of the abdomen (see fig. 24) is, as in 

 the forms belonging to the preceding family, divided into 

 4 separate plates. 2 very narrow ones in the middle and 

 2 broader lateral plates. The median plates, immediately 

 contiguous to each other, are of a linear form, and term- 

 inate each in 2 triangular points. The lateral plates are 

 semi-oval, and. on the outer side. uniformly arched. (bi 

 the inner side of the latter plates (see fig. 25). occurs 

 near the extremity a peculiar, hook-shaped appendix, which. 

 at the base, posteriorly, has a small, rounded lobe. This 

 appendix is movable by means of specially adapted muscles, 

 distinctly seen converging toward its base. That we have 

 here to do with accessory organs of copulation is. I think, 

 unquestionable ; though as yet it remainstobe shown what 

 particular function the said parts perform in the act. 



