167] PROTEOCEPHALIDAE—LA RUE 167 



PROTEOCEPHALUS FOSSATUS (Riggenbach) 

 [Figs. 133, 180] 



1896: Ichthyotaenia fossata Riggenbach 1896:166-193 



1911 : Proteocephalus fossatus La Rue 1911 :475 



Specific Diagnosis: The characters of the genus. Cestodes of 

 short length, 3.5-4 cm. long. Scolex large, visible to nailed eye, maximum 

 breadtli of same 0.714 mm. Anterior end of scolex conical, bearing at 

 apex a slight concavity, not a fifth suclier. Sucliers, round, 0.34 mm. in 

 diameter, borne at broadest part of head. Neck broad, 0.85 mm. long. 

 First proglottids broader than long, 0.612 mm. broad by 0.135 mm. long. 

 Mature and ripe proglottids, quadrate to longer than broad, End- 

 proglottids not observed. Lateral margins of proglottids quite straight^ 

 about the genital sinus a slight elevation or genital papilla. 



Genital aperture marginal, irregularly alternating, situated a little 

 anterior to the middle of the proglottid. Testes, numerous, 120-150, in 

 medullary parenchyma between vitellaria. Vas deferens, a loose mass 

 of coils between cirrus-pouch and middle of proglottid. Ductus ejacu- 

 latorius with few coils. Cirrus short and thicl^. Cirrus-pouch pear- 

 shaped, 0.30 mm. long, extending about y^ across the proglottid breadth. 

 Vagina, opening anterior to cirrus-pouch. Vaginal sphincter small, 

 near opening. Lumen of first part of vagina broad, nearly as large as 

 cirrus-pouch. No coils in vagina anterior to ovary. Arrangement of 

 organs in interovarial space typical of genus. Ovary bilobed, posterior. 

 Vitelline glands follicular, lateral, extending full length of segment. 

 Uterus in ripe proglottid with many lateral outpocketings on either side. 

 Eggs, round, thin shelled structures, size not given. 



Habitat : Intestine of Pimelodus pati Valenc, Rio Paraguay, South 

 America. 



This species was described by Riggenbach (1896) who made it a 

 member of the genus Ichthyotaenia. La Rue (1911) listed this species 

 in a list of species of Proteocephalus. The material was collected by Dr. 

 Ternetz in January and February 1894. The following description is 

 based on Riggenbach 's (1896) paper. 



The worms as collected were of small size, 3.5-4.0 cms. long. There 

 was no undamaged strobila. The neck is 0.85 mm. long and is quite 

 broad. It passes imperceptibly into the youngest proglottids. The 

 scolex (Fig. 133) is relatively large, and is perceptible to the naked eye. 

 It bears four large suckers at its broadest zone. Here the scolex is 0.714 

 mm. broad. From this point the scolex becomes smaller toward the 



