(;i)8 



is proposed as a new species (Taenia Kiabbei) and its external 

 ciiaraelers are discussed." 



The status of this species cun not Ije judged at present, but 

 the slight variation in the form of the hooks is not, in my 

 opinion, sufficient to establish the form. As Kowalevvski has 

 unfortunately written in a language which is not understood 

 by many authors, it Is difficult to judge his work, and as it 

 is now necessary for an investigating helminthologist to learn 

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

 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 

 own. 



Whatever may prove to be the status of this species, the 

 name T. Krabbei can not be retained for it, as this name has 

 always been used by Moniez for another form. 



17. DREr.\N/DOTAENIA TENUIROSTRIS (Rudolph!, 1819) RailUet, l89;v 



(1819, Taenia tenuirostris Rudolphi.) 



[PI. XIV, figs. 165-172.1 



Diagnosis: 100mm to 12'5mm long, 1mm to 3mm broad. Head 

 subglobular; rostellum delicate, subclaviform, armed with a 

 single crown of 10 hooks 20 fJi to 23 /flong; 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, 85 

 u. long. Hooks of oncosphere 7 fi. 



Development: Cercocystis Dr. tenuirostris in Gammarus 

 pulex, found by Hamann and von Linstow; in Cyclops agilis 

 and C. pulchellus found by Mrazek. 



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

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

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

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

 (Somateria moUissima); velvet scoter (Oidemia fusca); kit- 

 tiwake (Rissa tridactyla). 



Geographical distribution: Denmark, France, Germany, and 

 Bohemia. No epidemics recorded. 



Krabbe (1869, pp. 291-292) examined Rudolphi's types and 

 found hooks upon the rotellum, although they had escaped 

 Rudolphi's attention. The original specimens were collected by 

 Bremser from Merganser merganser: von Siebold also found 

 this si'ecies in lh'« ^iinu' h<'Sf, in Haxaria and Krahbe found the 



