12 ILLINOIS BIOLOGICAL MONOGRAPHS [12 



lateral fields. Testes numerous, forming a single broad dorsal field be- 

 tween vitellaria. Uterus ventral, with many lateral pouches. Genital 

 pore marginal, irregularly alternating. Ovary bilobed and situated 

 partly within and partly outside the inner muscle-sheath. Sexual organs 

 in general as in Proteocephalidae. In Siluridae. The type of the genus 

 is Monticellia coryphicephala (Tetracotylus coryphicephala Monticelli). 



The position of this genus in the order Tetraphyllidea is difficult to 

 determine. It apparently does not belong to any of the families as now 

 defined therefore the writer suggests for it the family name Monticelli- 

 dae with the following characters: Head small. Suckers sessile and 

 without accessory areola. Internal anatomy as in the type genus Monti- 

 cellia. 



There still remains the question as to whether the name Proteo- 

 cephalus is available. That name has been objected to on account of the 

 name Proteocephala suggested by de Blainville (1828) for a cestode 

 family. These two names are not homonyms and it is agreed that the 

 use of a name to designate a family does not invalidate it for use subse- 

 quently as a generic name. The writer therefore retains the name 

 Proteocephalus Weinland as the generic designation for the genus of 

 which Taenia filicollis Rud. is the type. 



Having determined that Monticellia coryphicephala (Monticelli) 

 does not belong in the family Proteocephalidae because of its peculiar 

 organization, it is necessary to redefine that family thus : Family Pro- 

 teocephalidae : Heads small. Suckers sessile and without accessory 

 areola. Fifth sucker functional, vestigial, or lacking. No rostellum. 

 Genital organs in general as in other Tetraphyllideans. Genital pores 

 marginal, irregularly alternating. Vitellaria lateral, follicular, follicles 

 closely grouped about a central conducting tubule. Ovary bilobed, 

 posterior. Oocapt, ootj^pe, shell gland, uterine passage present. Uterus 

 with lateral outpocketings and one or more preformed ventral uterine 

 openings. Vitellaria, testes, ovary and uterus within the inner longi- 

 tudinal muscle-sheath. 



Habitat : In fresh-water fish, amphibia, and aquatic reptiles. 



In this family belong the following genera which are here defined: 



(1) Proteocephalus Weinland 1858 



With characters of the family. Head globose or conical, flattened 

 dorsoventrally. No rostellum. No spines or hooks. No fold of tissue 

 encircling base of head or enfolding suckers. Suckers circular or oval. 

 Fifth sucker functional or vestigial, rarely lacking. Testes in a broad 

 field between vitellaria. Parenchyma with close meshes. Musculature 

 well developed. Eggs with three membranes. Habitat : In fresh-water 

 fish. 



