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The following larval stage is very like the preceding one, but the fifth limb is somewhat
more differentiated. The sixth limb is distinctly two-jointed; its proximal joint has one bristle,
its distal joint none. The furca has the same number of claws as in the preceding stage, but
the difference between main claws and secondary claws is less striking.
The next larval stage is characterized by the faet that the sixth limb has almost a
definitive shape, but it has comparatively few bristles; according to pl. 34, fig. 24 the end joint
has onlyfive bristles, three anterior ones and two posterior ones;the cleaning limb is developed
as a short, unjointed, upward pointing appendage without bristles. The furca has eight claws.
With regard to the further development of this form this author writes as
follows, p. 185: „lieber die weiteren Entwicklungsstadien kann ich für Cypridina
mediterranea keine Angaben machen. Nach Untersuchungen an Pyrocypris dürften noch
verschiedene Häutungen folgen. Die Veränderungen würden, abgesehen von einer allgemeinen
Größenzunahme und einer Vermehrung der Borsten an verschiedenen Gliedmaaßen, in
einer Streckung des Putzfußes bestehen, verbunden mit dem zunächst nur
andeutungsweisen Auftreten von Gliedern vmd dem Erscheinen einzelner Borsten an der Spitze.“
According to C.C’LAUS, 1865,p.
153,theyoung-est larval stage (whichis still in the brood chamber)
is quite without the two posterior pairs of limbs.
It follows from this that the results
obtain-ed by these authors agree very well, on the
whole, with what I observed above for
Cypridina (Doloria) pectinata. There are, however,
some small differences to note: thus, for instance,
in the third larval stage of Cypridina (Varyula)
mediterranea, which seems to correspond to
Stage III of Cypridina (Doloria) pectinata, the
cleaning limb is very short. Stage V and Stage VI
seem to have been confused by G. W. MULLER;
they seem to correspond to the youngest larval
stage given by this author.
Measurements: —
Sixty free-living individuals of Cypridina
(Doloria) pectinata from the above-mentioned
station were measured. The results of these
measurements are given in fig. XX.
The column 17—21 comprises the
embryos in the brood chamber; when these leave
the mother they probably have a length of
about twenty divisions. A mature male measured
62 divisions. The mature females are represented
by columns 73—76 and 77.
Fig. XX. — Curvesshowing the results of my
meas-uremeuts of the lengths or the shells of a number
of larvae of Cypridina (Doloria) pectinata from Tierra
del Fuego. — = females and voung larvae; .........
= males. The abscissa represents the lengths of the
shells expressed in divisions of a micrometer (29—30
divisions = 1 mm.); the ordinate represents Ihe number
of specimens measured.
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