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120
Gen. 11. Ammothea, Leach. 1815.
S vu. Achelia. Hodge.
Slægtscharaeter. Legemet kort og undersætsigt, med
tæt sammentrængte Sidefortsatser. Hovedsegmentet
massivt, med utydelig Hals og qvadratisk Pandedel.
Halesegmentet ikke sondret fra sidste Kropssegment, smalt
cylindriskt, horizons®. Øieknuden nær Forkanten af
Hoved-segmentet. stærkt ophøiet med tydelige Lindser. Snabelen
skraat nedadrettet, indknebet ved Basis, tenformig.
Sax-lemmerne hos fuldt udviklede Individer meget smaa,
2-led-dede, sidste Led kugleformigt. Følerne af middelmaadig
Længde, 8—9-leddede. De falske Fodder forholdsvis korte,
uden tydelig’ Endeklo og med et meget ringe Antal af
saugtakkede Randtorner. Gangfødderne korte og robuste,
ofte piggede; Laarleddet meget bredt, med det ydre Hjorne
mere eller mindre fremspringende; Tarsalleddet særdeles
lidet: Fodleddet kraftigt udviklet, mere eller mindre
krummet og pigget i Inderkanten; Endekloen stærk, Bikløerne
vel udviklede. Kjonsaabningerne hos Hannen beliggende
paa Spidsen af et stærkt Fremspring paa 2det Hofteled
af de 2 bagre Fodpar.
Bemærkninger. Slægten Ammotliea blev først
opstillet af Leach for en exotisk Art, hos hvem Saxlemmerne
endte med en liden, men tydeligt udviklet Chela. 1 1864
undersøgte den engelske Naturforsker, Hodge, en Del smaa
Pycnogonideer, hvoraf nogle ganske stemmede overens med
Leach’s Slægt, medens andre, skjøndt forøvrigt temmelig
lige. mærkeligt skilte sig derved, at Saxlemmerne ganske
manglede Chela. Han saa heri en generisk Forskjel og
opstillede derfor for disse sidste Arter sin Slægt Achelia.
Denne Slægt blev ogsaa af andre Zoologer adopteret, ja
af Wilson endog stillet i en ganske anden Familie end
Slægten Ammotliea. Forst Hoek har til fuld Evidens
godtgjort, at begge Slægter hører sammen, idet Slægten
Ammotliea kun grunder sig paa yngre Exemplarer, medens
Slægten Achelia repræenterer de fuldt udviklede Individer.
En betydelig Reduction af de under begge Slægter
opstillede Arter bliver derfor ogsaa nødvendig. Foruden den
først opstillede Art, A. carolinensis, Leach, og de 2
nedenfor nærmere beskrevne Arter, horer herhen en engelsk Art,
A. longipes, Hodge, en amerikansk, A. spinosa, Stinipson,
og 6 middelhavske Arter, nylig characteriserede af Dohrn
i hans Pycnogonideværk.
38. Ammothea echinata. (Hodge).
(Fl.Will, Fig. 1, a—m).
Achelia echinata. Hodge, Ann. Mag. Nat. Hist. Vol. XIII.
1864, p. 115. PI. XII, Fig. 7—10.
Ammothea brevipes, Hodge, ibid. p. 114, PI. XII, Fig.
1-4 (juv.)
Gen. 11. Ammothea. Leach, 1815.
Syn. Achelia, Hodge.
Generic Characters. Body short and stout, with
closely crowded lateral processes. Cephalic segment
massive, with indistinct neck and square frontal part.
Caudal segment not separated from the last body-segment,
narrow cylindric, horizontal. Ocular tubercle near the
front of the cephalic segment, strongly protuberant,
with distinct lenses. Proboscis directed obliquely
downwards, constricted at the base, fusiform. Chelifori, in
fully developed specimens, very small, 2-jointed, last
joint globular. Palpi of medium length, 8—9-jointed.
False legs relatively short, without distinct terminal claw
and with a very small number of serrated marginal spines.
Ambulatory legs short and robust, frequently spinous;
femoral joint very broad, with the outer corner more
or less projecting; tarsal joint particularly small;
propodal joint strongly developed, more or less curved and
spinous on the inner margin; terminal claw strong,
auxiliary claws well developed. The sexual apertures, in the
male, situated at the point of a prominent projection on
the 2nd coxal joint of the 2 posterior pairs of legs.
Remarks. The genus Ammothea was first established
by Leach for the adoption of an exotic species in which the
chelifori terminated in a small but distinctly developed chela.
In 1864 the English naturalist Hodge investigated a number
of small Pycnogonids, of which a few quite corresponded
to Leach’s genus, while others, although otherwise pretty
similar, distinguished themselves notably by the chelifori
being quite awanting in chela. He regarded this as a
generic difference, and therefore established for those latter
species his genus Achelia. This genus was also adopted
by other zoologists, indeed even placed by Wilson in quite
another family than the genus Ammothea. Hoek was the
first who completely established that both genera belong
to each other, as the genus Ammothea is only based on
young specimens, while the genus Achelia represents the
fully developed individuals. A considerable reduction in
the species ranked under both genera became therefore
necessary. Besides the first established species, A.
carolinensis, Leach, and the 2 species more particularly
described hereafter, there also pertain to it. an English
species A. longipes, Hodge, an American one. A. spinosa,
Stimpson, and 6 Mediterrannean species, lately
characterized by Dohrn in his work on Pycnogonida.
38. Ammothea echinata, (Hodge).
(PI. XIII fig. 1, a—m).
Achelia echinata, Hodge, Ann, Mag. Nat. Hist. Vol. XIII,
1864, p. 115, Pl. XII, figs. 7—10.
Ammothea brevipes, Hodge, ibid. p. 114, Pl. XII, figs.
1-4 (juv,).
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