215] PROTEOCEPHALIDAE—LA RUE 215 



came. The writer has frequently found the species in Necturus from 

 Ohio and Indiana which had been brought to the laboratory for dissec- 

 tion. Fuhrmann's specimen was obtained from Prof. F. Zschokke who 

 received it from Prof. R. Burckhardt. 



Type : Prepared slides in collection of Fuhrmann. 



Fuhrmann (1895:218-226) described and delineated this species, 

 calling it Ichthyotaenia lonnbergii. Without attempting a description 

 of the species it was referred to by La Rue (1909 :43) as Proteocephalus 

 lonnbergii. In a more recent paper La Rue (1911:481) pointed out 

 that this was to be considered as a species of a new genus, Ophiotaenia. 



This study is based on slides and alcoholics in the collection of 

 La Rue. The material has been carefully compared with Fuhrmann's 

 preparations of the type which Professor Ward very kindly secured 

 for the writer's use. The material was thus found to be identical with 

 Fuhrmann's. Reference will be made from time to time to the work 

 of Fuhrmann (1895) from which certain data were secured. 



This form is more robust than 0. filaroides. It may reach a length 

 of 17.0 cm. or more. Fuhrmann's specimen, an immature worm, meas- 

 ured 19.0 cm. The worm is thin and flat. Its breadth varies consider- 

 ably. The maximum breadth in the writer's specimens was 1.275 mm. 

 Fuhrmann's material had a slightly greater breadth. The strobilation 

 is rarely distinct. The margins of the strobila are quite smooth. In- 

 frequently the posterior part of the worm may show a distinct strobila- 

 tion. The proglottids are attached by their full width. Transverse 

 folds are rare but shallow longitudinal furrows are not unco mm on. 

 The scolex (Fig. 119) is somewhat globose and is flattened dorsoven- 

 trally. On it are four prominent suckers situated on its broadest part. 

 In breadth the scolex varies from 0.50 to 0.60 mm. There is no rostel- 

 lum, no spines and no functional fifth sucker. The suckers are round or 

 oval in outline with deep cavities and a strong musculature. In length 

 the suckers vary from 0.24 to 0.25 mm. and the breadth from 0.14 to 

 0.22 mm. The opening of the more oval suckers measures about 0.20 

 by 0.10 mm. Immediately behind the head the neck has a breadth of 

 0.375-0.54 mm. The first traces of segmentation occur about 2 mm. 

 posterior to the head. 



Young proglottids, according to Fuhrmann, measure 0.27 mm. in 

 length. The first discernible proglottids in the writer's material are 

 about 0.050 mm. long by 0.50 mm. broad. The length and breadth of 

 the proglottids increase rapidly for a distance then the length increases 

 while the breadth decreases. In this material the maximum breadth of 

 1.275 mm. was reached long before the proglottids were mature. Pro- 



