276 ILLINOIS BIOLOGICAL MONOGRAPHS [276 



small genital papilla. The length of the cirrus-pouch and the relations 

 of the latter with the vagina could not be ascertained. The testes num- 

 ber about 100 or more, and they are situated in a single field between 

 the vitellaria. The vitellaria are lateral follicular organs, the follicles 

 of which are scattered much as they are in Monticellia coryphicephala. 

 The ovary is bilobed, and it occupies a posterior position on the pro- 

 glottid. The material, however, is too poor to permit of a careful study 

 of this organ. The uterus could not be seen. 



This species belongs in the genus Monticellia La Rue. It is differ- 

 entiated from the other species of the genus by reason of its larger head 

 and suckers, its prominent genital pore and its evident segmentation. 

 Unfortunately the material is so poor that a careful study is not per- 

 mitted and as a consequence its exact relation to the other species of 

 the genus cannot be determined. 



MONTICELLIA DIESINGII (Monticelli) 

 [Fig. 157] 



1891 

 1896 

 1911 



Tetracotylus diesingii Monticelli 1891 



Ichthyotaenia diesingii Riggenbach 1896 :267 

 Monticellia diesingii La Rue 1911 :474 



This species was very inadequately described by Monticelli (1891) 

 whose material was too limited and too poor to permit a careful study. 

 Riggenbach (1896:267) listed it as one of the species of Ichthyotaenia 

 but gave no description of it. La Rue (1911:474) included this form 

 among the species of Monticellia. Monticelli 's original description is 

 here quoted: "TAENIA DIESINGII.— Capo subgloboso anterior- 

 mente rotendato appena distinto dal collo. Le quattro ventose grandi, 

 proeminente e molto muscolari. Collo assai lungo: prime proglottidi 

 brevissime appiattite, proglottidi mediane alquanto rigonfie all' aspetto 

 cerciniformi, posteriori rettangolari, ultime subquadrate. Aperture gen- 

 itali irregolarmente alternanti. L'apparato genitale, da quanto mi e 

 riuscito vedere, si assomiglia a quello della T. coryphicephala. 



Habitat: intestino del Silurus dargado." 



Thanks to Professor H. B. Ward the writer has been able to exam- 

 ine Monticelli 's type slides of this species and can add the following 

 data to the original description. 



The head is about 0.30 mm. in breadth. Suckers measure about 

 0.17 mm. in their maximum dimension while the opening of the same is 

 about 0.08 mm. long. The musculature of the sucker is thick. Altho 



