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134
ei- særdeles bevægeligt forbundne med hinanden ved en
ganske tynd Stilk, saa at det sidste kan slaaes ind mod
det förste. Endekloen er særdeles liden, stiletformig og
næsten ganske skjult mellem de fra sidste Led udgaaende
Fjærborster (se 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 Heste tydeligt anlagte i Fonn af smaa
fra Basis af de 4 förste Fodpar udgaaende Lapper (se Fig.
2 og 3). t
Bagkroppens Operculum (se Fig. 2 og 3) er særdeles
stort og hvælvet, indtagende Størsteparten af
Bagkropsseg-mentets Underside. Det viser langs ad Midten en stump
Kjol. der i den ydre Del spalter sig i 2 divergerende Grene.
Kanterne er ganske glatte.
De under Operculet liggende Buglenimer er alle ægte
respiratoriske og af en særdeles blod og tander Structur.
Det lste 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. De 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
tvegrenede, med den indre Gren omtrent af Basaldelens
Længde, dell ydre betydelig mindre. Begge Grene er af
lineær Form og forsynede med nogle meget smaa og fine
Børster.
Hannerne skiller sig ikke i sit ydre meget væsentligt
fra Hunnerne, men kjendes dog let ved lste Par Foleres
stærkere Udvikling og ved den eiendommelige Bygning af
Bagkroppens Operculum.
lste Par Følere (Fig. 23) er kjendeligt længere end
hos Hunnen, hvilket skyldes den langt stærkere Udvikling
af Svøben, der er forholdsvis mere end dobbelt saa lang
og sammensat af et særdeles stort Antal af Led.
Bagkroppens Operkiilum (se Fig. 24| er. som hos de
til foregaaende Familie hørende Former delt i 4 særskilte
Plader, 2 ganske smale i Midten og 2 bredere Sideplader.
De mediane Plader, der ligger i umiddelbar Contact med
hinanden, er af lineær Form og ender hver med 2
triangulære Spidser. Sidepladerne er af halvoval Fonn og
paa den ydre Side jevnt hvælvede. Paa den indre Side
(se Fig. 25) findes nær Enden et eiendommeligt krogformet
Appendix, der ved Boden bagtil viser en liden afrundet
Lap. Dette Appendix kan bevæges ved særegne Muskler,
der tydeligt sees at convergere mod Basis af samme. At
vi her har at gjøre med Hjælperedskaber ved Copulationen
er vel utvivlsomt; dog er det endnu ikke med Sikkerhed
oplyst, hvorledes disse Dele herunder fungerer.
in size, has a regular elliptic shape. Both articulations
are very movably connected by an exceedingly narrow
stem, which admits of the latter being jerked back toward
the former. The terminal claw is very small, styliforni,
and well-nigh wholly concealed amidst the plumous bristles
(see fig. 19) issuing from the last articulation.
The marsupium did not in any of the specimens
collected occur fully developed; but 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
exceedingly 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 outer part,
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
delicate in structure. The 1st pair (fig. 20) are distinctly
bi-ramous, with the inner branch forming a broad, rounded
plate, consisting of 2 indistinctly defined segments; the
outer is quite narrow, cylindric. and somewhat curved,
composed of 2 distinct articulations, ciliated along the outer
margin. The remaining pairs would appear to form merely
simple, irregular-folded plates (fig. 21).
The caudal appendages (fig. 22), jutting forth on either
side of the obtuse projection formed in the middle,
posteriorly. by the abdominal segment, are exceedingly small,
but distinctly birainous. 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 bristles.
The males do not differ essentiably in their outer
habitus from the females, but are nevertheless easily
recognized by the fuller development characterizing the 1st
pair of antennæ, as also by the peculiar structure of the
abdominal operculum.
The 1st pair of antennæ (fig. 33) are appreciably
longer than in the female, a character arising from the
much fuller development of the flagellum, which is
relatively 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
terminate each in 2 triangular points. The lateral plates are
semi-oval. and. on the outer side, uniformly arched. On
the inner side of the latter plates (see fig. 251, 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 vet it remains to be shown what
particular function the said parts perform in the act.
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