6.13 Paradoxostoma magellanicum
M iiller, 1908
Paradoxostoma magellanica Mtiller, 1906b: p. 7,
figs. 12-15.
Paradoxostoma magellanicum Mtiller, 1912: p.
287.
Carapace length -
females: 0.56 mm
males: 0.65 mm (Mtiller, 1906b)
Female. Carapace mediumsized, subelliptical;
height a little more than 1/2 the length, greatest
height about medial; dorsum gently arched, anterior more narrowly rounded than the broadly
rounded posterior; ventral margin almost
straight, but weakly inflexed anteromedially.
Surface smooth; colour brownish. Inner lamella
broad, line of concrescence submarginal anteriorly, displaced further inwards ventrally and
posteriorly; vestibule large, broad anteriorly,
elongate posteriorly; 15-20 marginal pore canals. Normal pore canals scattered simple. Central adductors comprising a subvertical row of 4
or 5 scars, several of them divided; hinge adont.
Eye anterodorsal. Soft anatomy generally similar
to that of P. sp. aff. hypselum.
Male. Similar in shape and soft anatomy to the
female, except that the 3rd segment of the Al is
strongly hirsute; the maxillular palp is present
but represented by only a simple bristle, and the
first lobe of the maxillule is only 1/2 the length of
lobes 2 and 3. The anterior process of the hemipenis is lanceolate (Mtiller 1906b ).
Remarks
We identified only 5 individuals as belonging to
this species and none was male, so we were unable to check if the hemipenis matched the type
description. This is a disappointing result, as the
Straits of Magellan are the type locality for this
species and it has been described from nowhere
else. Interestingly, the single male on which the
type description is based was found associated
with the shell of Eurypodius latreillei (Mtiller
1906b).
Distribution
Known only from the Straits of Magellan.
M iiller, 1908
Paradoxostoma magellanica Mtiller, 1906b: p. 7,
figs. 12-15.
Paradoxostoma magellanicum Mtiller, 1912: p.
287.
Carapace length -
females: 0.56 mm
males: 0.65 mm (Mtiller, 1906b)
Female. Carapace mediumsized, subelliptical;
height a little more than 1/2 the length, greatest
height about medial; dorsum gently arched, anterior more narrowly rounded than the broadly
rounded posterior; ventral margin almost
straight, but weakly inflexed anteromedially.
Surface smooth; colour brownish. Inner lamella
broad, line of concrescence submarginal anteriorly, displaced further inwards ventrally and
posteriorly; vestibule large, broad anteriorly,
elongate posteriorly; 15-20 marginal pore canals. Normal pore canals scattered simple. Central adductors comprising a subvertical row of 4
or 5 scars, several of them divided; hinge adont.
Eye anterodorsal. Soft anatomy generally similar
to that of P. sp. aff. hypselum.
Male. Similar in shape and soft anatomy to the
female, except that the 3rd segment of the Al is
strongly hirsute; the maxillular palp is present
but represented by only a simple bristle, and the
first lobe of the maxillule is only 1/2 the length of
lobes 2 and 3. The anterior process of the hemipenis is lanceolate (Mtiller 1906b ).
Remarks
We identified only 5 individuals as belonging to
this species and none was male, so we were unable to check if the hemipenis matched the type
description. This is a disappointing result, as the
Straits of Magellan are the type locality for this
species and it has been described from nowhere
else. Interestingly, the single male on which the
type description is based was found associated
with the shell of Eurypodius latreillei (Mtiller
1906b).
Distribution
Known only from the Straits of Magellan.