Is proposed as a new spei-ies ('I'iieiiiii Kialiljeii and its exlenial 

 characters are discussed." 



The status oC this species can not be judged at present, but 

 Uie slight variation in the forni of the hoolvs is not. in my 

 opinion, sutflcient to establish the form. As Kowalewski has 

 unfortunately written in a language which is not understood 

 by many authors, It is dilflcult to judge his work,, and as it 

 is now necessarj' for an investigating helminthologist to learn 

 no less than ten languages in order to keep up with his brancli, 

 it is to be hoped that Kowalewski will in the future give full 

 translations of his scientific articles in German, French, Eng- 

 lish, Italian, or some other language better known than his 



Whatever may prove to be the status o£ this species, the 

 name T. Krabbei can not be retained for it, as thi.« name ha.< 

 always been used by Moniez for another form. 



17. URlSPANiDOTAENlA TLN'UIROSTRIS (Rudolphl. 1819) Rallllct, 189,i 



(1S19, Taenia tenuirostria RuUolphi.) 

 [PI. XIV. figs. 165-172.1 



Diagnosis: lOO'unJ to 125n>m long, l"i"i to Smm broad. Head 

 subglobular; rostellum delicate, subclavltorm, armed with a 

 single crown of 10 hooks 20 /« to 23 /* long; suckers round. Neck 

 rather long. "Anterior segments straight and short, the follow- 

 ing longer, with sharp prominent posterior angles, like the 

 teeth of a saw. Genital pores unilateral. Egg cylindrical, Su 

 « long. Hooks of oncosphere 7 fi. 



Development: Cercocystis Dr. tenuirostris in Gammarus 

 pulex. found by Hamann and von Linstow: in Cyclops agllis 

 and C. pulchellus found by Mrazek. 



Hosts: Tame goose (Anser anser dom.): European scaup 

 duck (Aythya marila); tufted duck (Aythya cristata); 

 goosander (Merganser merganser); red-breasted merganser (M. 

 serrator); smew or nun (Mergus albellus); Greenland eider 

 (Somateria mollissima); velvet scoter (Oidemia fusoa); kit- 

 tiwake (Rissa tridactyla). 



Geographical distribution: Denmark. France, Germany, and 

 Bohemia. No epidemics recorded. 



Krabbe (1S69, pp. 291-292) examined Rudolphl's tyipes and 

 found hooks upon the rotellum. although they had escaped 

 Rudolphl's attention. The original specimens were collected by 

 Bremser from Merganser merganser: von Siebold also found 

 this species in the same host in l?a\aria and Krabbe fmind the 



