PREFACE. 



The present treatise is based for the most part on studies carried out by mc at the Zoo- 

 logical Institution of the University of Upsala on material belonging to the Swedish State 

 Museum (Riksmuseiim), Stockholm. For the purpose of carrying out verificatory investi- 

 gations smaller collections have also been furnished by the Zoological Museum of 

 the University of Upsala, the Ch r i s t i a n i a Zoological Museum, the 

 Copenhagen Zoological Museum and by Professors G. W. MUller, Greifswald 

 and G. S. BRADY, Sheffield. In addition the Ostracod material brought home by the ,,M i c h a e 1 

 S a r s North Atlantic Deep Sea Expedition", 1910 has been kindlv entrusted to me for examination. 

 — ■ In order to study the oecology of the marine s t r a c o d s and to collect material for this 

 group of animals I have spent some summer months (assisted partly by grants from the 

 Swedish Royal Academy of Science) at the west coast of Sweden (the Zoological Marine Station 

 at Kristineberg) and from December 1915 till June 1916 (with a grant from the C. F. 

 LlLJEV^'ALCH's travelling scholarship fund) at the Labotatoire Russe de Zoologie at Villefranche- 

 sur-Mer and the Musee Oceanographique de Monaco. 



Among the Ostracod collections in the Swedish State Museum I found the 

 original material of P. T. Cle\T2's work of 1900 (a part of which had been already published by 

 C. W. S. AURIVILLIUS in 1899). On re-examining this material I verified that Conchoecia bispinosa, 

 C. horealis, C. elegans and Microconchoecia Clausii (= Conchoecia curta J. LUHi^OCK) were 

 correctly determined. On the other hand Paraconchoecia oblonga was incorrectly determined; 

 the specimens on which this statement was based turned out to belong to Euconchoecia Chierchiue 

 G. W. MOli.eu. See these species below. There was only a single specimen of Conchoecella 

 (= Conchoecia) acuminata; this was a male which was not yet mature (presumably belonging to 

 I he oldest larval stage). The length of this specimen was 2,1 mm.; the number of furcal claws 

 seven. As far as could be seen the correctness of its determination was fairly certain. 



In the collections of this museum there is also a part of the original material of Conchoecia 

 horealis, C. elegans and C. ohtusata in P. T. Cleve's work of 1903 (= P. T. Cle\e and 0. PettersSON, 

 1903). On re-examining this material I found that the determinations were correct. 



In the collections of tlie Zoological Museum of the University of 

 Upsala I found tlie original material of Philomedes globosus and Cypridinu Reynaudii, 



Zoolog. bidrag, Uppsnla. Siippl.-Bd. I, 



