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The disco ver er o f
these forms.
The development of
o ur knowledge of the
different organs.
The development of
the classification of
the Halocyprids.
As is seen above (p. 155), the Halo c y p r i d s were iutroduced into the litera ture
by J. 1). Dana. In his monumental work of 1852 this investigator gave a rather thorough and
in some respects meritorious description of the general morphology of this group. The
morphologica! value of the first and second antennae and of the mandible and the furca was thus
correctly conceived, and these organs were described in a fairly satisfactory manner. A
description that was on the whole correct was also given of the rod-shaped organ, ,,the exsertile
spiculum“; on the other hånd nothing was stated as to the nature of this organ. But this writer
made more or less serious mistakes in the explanation and description of the posterior limbs.
It is true that the maxilla was explained correctly, „the first pair of maxillae“, but its
description is rather deficient. This author denoted the endite on the procoxale of the maxilla
+ the epipodial appendage of the fifth limb -f- the seventh limb as the „second pair of
maxillae“; the sixth limb was taken as the „first pair of feet“ and the fifth limb without the
epipodial appendage as „the second pair of feet“. The description of these organs is also rather
deficient. An additional mistake was committed by this writer; he thought that he had found
in one species „two simple eyes near the medial line, just posterior to the base of the tentacles“.
G. 0. Sars’s work of 1865 indicates a great advance, though unfortunately it is not
illustrated. It may be said that the general morphology of the genus Conchoecia became fairly
well known from this work. All the limbs were correctly explained and were described in a way
that was on the whole very satisfactory; the sexual dimorphism of the first and second antennae
and the sixth limb was pointed out; the upper lip and the male copulato ry organ were
described, though only in very general terms; the absence of eyes was established (for the
occurrence of these organs in the first antenna see p. 560 above). This writer even perhaps observed
the heart, but he only speaks indistinctly on this point (it is not quite clear if he means that
the whole group Myodocopa is eharacterized by this organ or if it is only found in a number
of representatives of this group; cf. p. 6).*
After this work our knowledge of the morphology of the Halocvprids has been
inereased still further. The most important works are the following: C. Claus, 1874 b and
1891 a, G. O. SARS, 1887 and G. W. MÜLLER, 1890 a and 1894. The most important of these
works is perhaps the last-mentioned of C. Clals’s, which is equally distinguished by its
coin-prehensiveness as by its wealth of detail ; this work made the Halocvprids the best
known group arnong the marine Ostracods and one of the best known among all Crustacea.
G. W. Müller’s Naples monograph is the last work in which the morphology of the H
alocyprids is dealt with in detail.
In a preliminary work (1849) J. I). Dana eollected all the species of this group
invest-igated by him into a single genus, Conchoecia, and in 1852 he divided them into two genera,
Conchoecia and Halocypns. From these genera this writer formed the sub-family Halocyprinae,
which was grouped together with the sub-family Cypridininae to form the family Halocypridae;
cf. p. 155 above. — The descriptions of the genera Conchoecia and Halocypris were, however,
exceedingly incomplete and partly incorrect as well. One result of this was that the succeeding
authors formed a more or less coinpletely erroneous idea of these genera; they were quite confused
• OLherwise C. Ci.aus, 1874 l>. p. 5, was the first to observe this organ.
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