73] PROTEOCEPHALIDAE — LA RUE 73 



Kraemer in his paper gave no adequate reasons for considering that 

 the Taenia filicollis and Taenia ocellata of Rudolphi were identical. His 

 specimens were neither from Rudolphi 's type host nor from his type 

 locality but from a very different host and locality. Zschokke had ma- 

 terial from Perca fluviatilis yet he described what he considered to be 

 Taenia filicollis rather than Taenia ocellata from that host. Neither 

 Zschokke nor Kraemer reported parasites from Gasterosteus aculeatus or 

 O. pungitius, neither of which occur in the waters from which their fish 

 came. Kraemer 's specimens beyond a doubt belong to the species P. 

 fallax La Rue. Riggenbach (1896) accepted Kraemer 's conclusion con- 

 cerning the identity of Taenia ocellata and Taenia filicollis. He appar- 

 ently made no comparative study of the forms. From North American 

 fish Benedict (1900) described a species which he considered identical 

 with Kraemer 's Taenia ocellata and so named it Proteocephalus ocellata 

 (Rud.). That however was a misdetermination, for Benedict's specimens 

 have been shown to belong to another species (see P. exiguus La Rue). 

 Nufer (1905) may have been dealing in part with this species in his 

 statements regarding P. ocellatus and P. longicollis from Coregonus fera. 

 La Rue (1911 :476-477) described this as a new species, P. fallax. 



The material on which this species is based bears the label "T. ocel- 

 lata, Coregonus fera." It was secured from Prof. Fritz Zschokke by 

 Prof. H. B. Ward. It now bears the number 09.9 in Professor Ward's 

 collection. Some of this material was stained in haematoxylin and 

 mounted in balsam. Other specimens were cleared in glycerine. 



A comparison of these preparations with Kraemer 's description 

 made evident the fact that this species and Kraemer 's Taenia ocellata 

 are anatomically identical. The fact that Kraemer 's specimens were 

 also from Coregonus fera and that doubtless they came from the same 

 locality was one of the considerations which caused this identity to be 

 suspected. Kraemer 's descriptions of T. ocellata will be used as sources 

 of comparative data, all of his data being grouped together. 



The larger worms at the writer's disposal were unfortunately 

 broken into pieces. One complete strobila measured 27 mm. long with 

 a maximum breadth of 0.459 mm. A small piece in the same lot had a 

 maximum breadth of 1.20 mm. Kraemer reported specimens of T. ocel- 

 lata 30-60-100 mm. long. He reported a breadth of 0.114 mm. for the 

 head and 0.038 mm. for suckers. The last measurement must be that 

 of the sucker opening and not the maximum diameter of the sucker. 



