186 ILUNOIS BIOLOGICAL MONOGRAPHS [186 



Geschlechtsdrusen sowie auch solche mit Uterus annahemd quadratisch. Genital- 

 offnung in der Mitte des Gliedrandes. Cirrusbeutel klein, kaum uber den Dot- 

 terstock nach innen hinausragend ; das Knauel des Vas deferens stark querge- 

 streckt, vom Cirrusbeutel bis an die Medianlinie reichend. Hodenblaschen sehr 

 zahlreich, das ganze Mittelfeld der Proglottis einnehmend. Vagina ohne Sphincter. 

 Uterus jederseits mit etwa 6-8 schlanken, sich etwas verzweigenden Seitenasten. 

 Kalkkorperchen anscheinend sparlich. 

 "Im Darm von Silurus giants L." 



La Rue (1911:475) listed this as a little known species of Proteo- 

 cephalus. 



The above diagnosis by Liihe and his drawing of the inner struc- 

 ture of the proglottid furnish the only available data on the anatomy 

 of this species. Unfortunately his drawing and description fail to show 

 many of the details which one might desire. If his interpretation of the 

 structures there found are correct then one must consider that so far 

 as the arrangement and character of the generative organs are con- 

 cerned this species must belong with the genus Proteocephalus. The 

 presence of the minute spines on the fifth sucker is not in strict accord 

 with the writer's ideas of this genus. At first glimpse one is caused to 

 think of the spines on the head of the members of the genus Acantho- 

 taenia and is led to inquire whether this species does not have its place 

 in that genus. However, since the Acanthotaenia are found thus far 

 only in the Varanidae, a family of lizards, it seems that this species 

 can not have its closest relatives there. Since its host is a member of 

 the genus Silurus and since this genus harbors several species of ces- 

 todes of the genus Monticellia one must consider the possibility of its 

 belonging with the latter. Here, it seems to the writer, this species will 

 eventually be placed but at present aU the data, meager tho they are in 

 details, place it in the genus Proteocephalus. 



TAENIA SIMPLICISSIMA Leidy 



1887 : Taenia simplicissima Leidy 1887 :22 



1891: Taenia simplicissima MonticeUi 1891 



1896 : Ickihyoiaenia simplicissima Riggenbach 1896 :267 



1911: Proteocephalus simplicissimtis La Rue 1911:475 



This species was first described in a very superficial way by Leidy 

 (1887) who besides the wholly inadequate species description figured 

 the head and the outline of the proglottids in two drawings. Monticelli 

 (1891) without comment included this species in a list of forms which 

 somewhat resembled his Teiracotylus (Taenia) coryphicephala. Rig- 

 genbach (1896) included this form in a list of species of Ichthyotaenia. 



