THE BALTIC SEA 



347 



Characeae 



Phanerogamae 

 Ciliata 

 Cnidaria 

 Turbellaria 



Rotatoria 



Nemertini 



Polychaeta 



Ostracoda 



Copepoda 



Cladocera 



Decapoda 



Isopoda 



Tanaidacea 



Amphipoda 



Coleoptera 



Gastropoda 

 Bryozoa 



Tolypella nidifica, Chara baltica, Ch. canescenes (Ch. 



crinitd) 



Scirpus parvulus, Zannichellia pedunculata, Najas marina 



Tintinnopsis tubulosa, T. brandti, Leprotintinnus bottnicus 



Protohydra leuckarti, Pelmatohydra oligactis 



Promesostoma baltica, P. cochlearis, P. lugubra, Koino- 



cystis twaerminnensis 



Synchaeta fennica, S. monopus, Anuraea cruciformis 



eichwaldi, A. quadrata platei, A. cochlearis recurvispina 



Prostoma obscurum 



Streblospio dekhuyzeni, Alkmaria romijni 



Cytherura gibba, Cytheromorpha fuscata 



Eurytemora affinis, E. hirundoides, Acartia bifilosa 



Bosmina coregoni maritima 



Palaemonetes varians 



Sphaeroma hookeri, Cyathura carinata, Idothea viridis 



Heterotanais oerstedi 



Bathyporeia pilosa, Melita palmata, Gammarus zaddachi 



zaddachi, G. z. salinus, G. duebeni, Leptocheirus pilosus, 



Corophium lacustre 



Ochtebius marinus, Laccobius decorus, Haemonia mutica, 



H. pubipennis 



Hydrobia ventrosa, Alderia modesta 



Membranipora crustulenta, Victorella pavida. 



However, this group can be considerably reduced since some of the animal 

 forms included (possibly as many as 15) are not endemic to the Baltic Sea. 

 Some of the forms enumerated have possibly not been adequately identified. 



Even if these endemic forms exist, their endemism is evidently very recent 

 and probably not sufficient to relate them to true brackish-water organisms. 

 Relict forms of much more ancient origin, which penetrated into the Baltic 

 Sea at a second stage, are much more deserving of this name. Remane 

 increases this list considerably, including 68 denominations of animals alone 

 (adding the Ice Age relicts and immigrants from other bodies of water). The 

 following forms from his list are not included in that of Sagerstrale given 

 above : 



Coelenterata 

 Turbellaria 



Rotatoria 



Polychaeta 



Cordylophora caspia 



Procerodes ulvae 



Acrorhynchus robustus 



Macrostomum hystrix 



Proales similis, Linasia tecusa, Eucentrum evistes, E. rous- 



seleti, Erignatha thienemanni, Aspelta baltica, Colurella 



dicentra, Notholca striata, N. bipalium, Brachionus plica- 



tilis, Euchlanis plicata, Synchaeta lavina, S. littoralis, 



Testudinella clypeata, Pedalia fennica 



Manayunkia aestuarina, Polydora redekei 



