280 ILLINOIS BIOLOGICAL MONOGRAPHS [280 



The systematic position of this species is not readily determined 

 from the data at hand. Fritsch's description leaves much to be desired 

 and his figures are not sufficiently definite to render possible a positive 

 determination. Nevertheless, certain features of the anatomy of the 

 worm are so well delineated that some definite conclusions can be 

 reached. The rounded summit of the head covered with numerous 

 spines and the very prominent suckers which seem to be set on the 

 surface of the head are not typical of Proteocephalus. Species of that 

 genus lack spines on the head and their suckers are never as prominent 

 as in the species under consideration. The head agrees very well with 

 that of Monticellia coryphicephala Monticelli in regard to the suckers. 

 The latter species has no spines. In the genital organs there seems, in 

 the main, to be a good agreement with the members of the genus Pro- 

 teocephalus. Nevertheless, a careful examination and comparison of 

 Fritsch's figure of the proglottid (Fig. 166) with the writer's figure of 

 Monticellia coryphicephala (Fig. 95) shows a certain resemblance that 

 cannot be overlooked. In both species there is the more or less indefi- 

 nitely outlined ovary made up of follicles at the outer regions. These 

 follicles seem to be smaller in this species than in M. coryphicephala. 

 The vitellaria, apparently, are not as extensive in the former as in the 

 latter, yet they are different from those in Proteocephalus. The lips 

 of the genital sinus are much more prominent in this species than in 

 Proteocephalus. This character was not mentioned by Monticelli as 

 being present in Tetracotylus nor has the writer noted it in his specimens. 



In view of the facts above presented the writer must conclude that 

 the species does not belong to the genus Proteocephalus Weinland. 

 With some reservation this species is assigned to the genus Monticellia 

 La Rue. The species is then to be known as Monticellia malopteruri 

 (Fritsch) La Rue. The species of cestodes infesting the Siluridae merit 

 much more careful study by modern methods. As yet their structure 

 and relationships are almost unknown. The literature contains but few 

 references to cestodes of this group. The writer has noted the descrip- 

 tions of the species Tetracampos ciliotheca Wedl and Marsypocephalus 

 rectangulus Wedl reported by Wedl (1861) from Heterobranchus an- 

 guillaris. The former because of its ventral genital pore, ciliated embryo 

 and two bothria evidently belongs to the order Pseudophyllidea. The 

 latter species may belong somewhere in the Proteocephalidae or Monti- 

 cellidae but not sufficient data are given to warrant a positive determi- 

 nation. Wedl (1861) also reported Scolex syndontis from Syndontis 

 schal and from Heterobranchus anguillaris. These specimens, likewise, 

 cannot be definitely placed. 



