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121
Ammothea fibulifera, Dohrn. Die Pantopoden ties Golfes
von Neapel, p. 141. Tab. IV, Fig. 1—22.
Ammothea eehinata. Hoek, Archives de Zool. experiment.
Vol. IX. p. 508, PI. XXV, Fig. i 4—16.
— G. O. Sars, Pycnogonidea borealia &
arctica, No. 38.
Artscharacter. Legemet tykt og massivt, noget
nedtrykt. 2det Kropssegment vel adskilt saavel fra
Hovedsegmentet som det folgende Segment; de 2 sidste
sammen-voxne. Pandedelens Sidehjørner udtrukne til koniske,
fortilrettede Fremspring. Sidefortsatserne tykke, næsten
sammenstødende, hver ved Enden oventil forsynet med 2 ens
udviklede pigformige Fortsatser endende med en stiv Børste.
Øieknuden noget fortilrettet, næsten cylindrisk. Spidsen
afstumpet, med et kort mediant Fremspring; Lindserne nær
Enden. Snabelen mere end halvt saa lang som det øvrige
Legeme. Saxlemmerne neppe halvt saa lange som
Snabelen. Skaftet oventil ved Enden gaaende ud i et i Spidsen
tvedelt og med 2 Pigge forsynet Fremspring, Endedelen
kngleformig. Følerne 8-leddede, temmelig tynde, 2det Led
længere end 4de, dette sidste kortere end Endedelen.
Gangfødderne neppe dobbelt saa lange som Legemet,
kraftigt byggede og delvis besatte med Pigge; de 2 første
Hofteled hos Hannen hvert med 4 parvis ordnede
pigformige Fortsatser, Laarleddets ydre Hjorne koniskt
fremspringende, Fodleddet næsten jevnt bredt, stærkt krummet
og bevæbnet ved Basis i Inderkanten med 3 stærke Torner;
Endekloen omtrent halvt saa lang som Fodleddet, Bikløerne
vel udviklede, af Kloens halve Længde. Farven gulägtig.
Legemets Længde 2™; Spandvidde 7""".
Bemærkninger. At denne Fonn er Hodge’s Achelia
eehinata, anser jeg for sikkert, og rimeligvis horer ogsaa
hans Ammothea brevipes herhen som repræsenterende det
endnu ikke fuldt udviklede Dyr. Ligeledes kan jeg ikke
tvivle paa, at Dohrn’s A. fibulifera er identisk med den
nordiske Form, hvad ogsaa Hoek antager. I Begyndelsen
var jeg ogsaa tilbøielig til at henføre den nordamerikanske
Form. A. spinosa (Stimpson) til denne Art, men finder
dog, at dømme efter den af Wilson givne Beskrivelse og
Figur, at der kan være Grund til at holde begge Former
indtil videre ud fra hinanden. Arten er let kjendelig ved
sine, især hos Hannen, stærkt piggede Fødder.
Beskrivelse. Længden af Legemet hos fuldt
udviklede Individer af begge Kjøn overstiger neppe ~2wm, og den
største Spandvidde er omtrent 7mm.
Legemets Form (se PI. XIII, Fig. 1 og 1 a) er
ualmindelig undersætsig og Fødderne kortere end hos nogen
af de i det foregaaende omtalte Former, med Undtagelse
af Slægten Pycnogonum. Selve Kroppen (Fig. 1 b. 1 c.
1 d) er forholdsvis meget tyk og har Sidefortsatserne saa
tæt sammentrængte, at det midtre Parti -af Legemet faar
Udseende af en oval Skive, hvorfra Lemmerne udstraaler.
Midt over Kroppen gaar 2 vel markerede Tværsuturer,
hvorved 2det Segment er tydeligt afgrændset saavel fra
Den norske Nordllavsexpeditiou. G. O. Sars: Pycnogonidea.
Ammothea fibulifera, Dohrn. Die Pantopoden des Golfes
von Neapel, p. 141. Pl. IV. figs. 1 —22.
Ammothea eehinata, Hoek. Archives de Zool. experiment.
Vol IX, p. 508. Pl. XXV, figs. 14 -10.
— G. O. .Sars, Pycnogonidea borealia &
arctica, No. 38.
Specific Characters. Body thick and massive,
somewhat depressed, 2nd truncal segment well separated from
the cephalic segment as well as from the succeeding one;
the two last segments coalesced. The lateral corners
of the frontal part drawn out to conical prominences
projected forwards. Lateral processes thick, almost
contiguous, each furnished at the end. above, with two equally
developed spiniform processes terminating in a stiff bristle.
Ocular tubercle somewhat anteriorly directed, almost
cylindrical, the point blunted, with a short medial
prominence; the lenses placed near the extremity. Proboscis
more than half as long again as the rest of the body.
Chelifori scercely half the length of the proboscis, the
scape at the tip, above, passing into a bifurcated projection
at the point furnished with 2 spiues, the terminal portion
globular in form. Palpi 8-jointed, rather slender, 2nd joint
longer than 4th and the last-named shorter than the terminal
part. Ambulatory legs scarcely twice as long as the body,
powerfully built and partly beset with spines; the 2 first
coxal joints, in the male, each with two spiniform processes
arranged in pairs, the outer corner of the femoral joint
conically projectant, propodal joint almost uniform in
breadth, strongly bent, and. at the base, furnished on the
inner margin with 3 strong spines; terminal claw about
half the length of the propodal joint, auxiliary claws well
developed and half the length of the claws. Colour
yellowish. Length of the body 2""". Extent 7""".
Remarks. That this form is Hodge’s Achelia
eehinata I consider to be certain, and probably his Ammothea
brevipes also belongs to it, as representative of the not
yet fully developed animal. Neither can I doubt that
Dohrn’s A. fibulifera is identical with the northern form,
which Hoek lias also supposed. At first I was also
disposed to assign the North American form. A. spinosa.
(Stimpson) to this species, but think, however, when judged
by the description and illustration given by Wilson, that
there may be good reason to keep both forms separate
from each other for the present. The species is easily
recognizable by its spinous legs, especially in the male.
Description. The length of the body, in fully
developed individuals of both sexes, scarcely exceeds 2mm and
the greatest extent is about 7’""’.
The body (see PI. XIII. fig. 1 and 1 a) is
uncommonly stout, and the legs shorter than in any of the forms
we have previously mentioned with exception of the genus
Pycnoyonum. The trunk itself (fig. 1 b. 1 c. 1 d) is
relatively very thick, and has the lateral processes so closely
crowded that the medial portion of the body aquires the
appearance of an oval disc from which the limbs radiate.
Across the middle of the body two well-defined
transversal sutures pass, causing the 2nd segment to be dis-
18
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