PREFACE. 



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

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

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

 gations smaller collections have also been furnished by the Zoological Museum o f 

 the University of Upsala, the Chris tiania Zoological Museu m, the 

 Copenhagen Zoological Museum and by Professors G. W. MClleh, 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 kindly 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 Krisfcineberg) and from December 1915 till June 1916 (with a grant from the C. F. 

 LlLJE\\ALCH's travelling scholarship fund) at the Labotatoire Russe de Zoologie at Villefranche- 

 sxir-Mer and the Musee Oceanographique de Monaco. 



Among the Ostracod collections in the Swedish State M u s e u m I found the 

 original material of P. T. Clf^vb's work of 1900 (a part of which had been already published by 

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

 C. borealis, C. elegans and Microconchoecia Clausii (= Conchoecia curia J. LunBOcilv) 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 EuconchoeciaChierchiae 

 G. W. MtlLLER. See these species below. There was only a single specimen of Conchoecetta 

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

 the 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 

 borealis, C. elegans and C. obtusata in P. T. Cle\b's work of 1903 (= P. T. Clenr and 0. PettersSO.V, 

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



In the collections of the Zoological Museum of the University of 

 Upsala I found the original mat(>rial of Philomedes globosus and Cypridina Reynaudii 



ZooloK. bidrag, Uppsala. SuBpl.-Bd. I. 



