562 TAGB SKOGSBERG 



Tlie di:icoverei- I'l As is seeii ubove (p. 155), the H a 1 (I (■ y p r i d a were introduced into the literature 



iie!,e fniiiis. j^^ J j^^^ Dana. In his mf)numental work of 1852 this investigator gave a rather thorough and 



The developiiiiiit "./ -j^ ^^^^j^^p respccts meritorious description of the general morphology of this group. The mor- 

 differeni organs, phological value oi the hrst and second antennae and oi the mandible and the lurca was thus 

 correctly conceived, and these organs were described in a fairly satisfactory manner. A de- 

 scription that was on the whole correct was also given of the rod-shaped organ, ,,the exsertile 

 spiculum"; on the other hand 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 de- 

 scription is rather deficient. This author denoted the endite on tlie procoxale of the maxilla 

 + the epipodial appendage of the fifth limb + 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 ajjtpendage 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 copulatory organ were de- 

 scribed, though only in very general terms; the absence of eyes was established (for the occur- 

 rence 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 Mt/odocopa is characterized 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 H a 1 o c y p r i d s has been 

 increased still further. The most important works are the following: C. Claus, 1874 b and 

 1891 a, G. O. SaPvS, 1887 and G. W. Mllleh, 1890 a and 1894. The most important of these 

 works is perhaps the last-mentioned of C. Glaus's, which is equally distinguished by its com- 

 prehensiveness as by its wealth of detail ; this work made the H a 1 o c y p r i d s the best 

 known group among the marine Ostracods and one of the best known among all Crustacea. 

 G. W. Muller's Naples monograph is the last work in which the morphology of the H a 1 o- 

 c y p r i d s is dealt witli in detail. 



7'A« drvrhpmen, »/ j^^ .^ preliminary work (1849) J. D. Dwa collected 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 Halocyfns. From these genera this writer formed the sub-family Halocyprinae, 

 which was grouped together with the sub-family Cypridininae to form the family Halocijpridae; 

 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 tliat the succeetling 

 authors formed a more or less comiiletely erroneous idea of these genera; they were ijuite confused 

 * OLherwisi' ('.. Ci.mis, IS7'i h. |). .'i, was the first to ohservr this orgai}. 



