240 ILLINOIS BIOLOGICAL MONOGRAPHS [240 



OPHIOTAENIA MARENZELLERI (Barrois) 



[Figs. 37, 199] 



1898 : Ichthyotaenia marenzelleri Barrois 1898 :2-3 



1908 : Ichthyotaenia marenzelleri Schwarz 1908 :26-27 



1911 : Ophiotaenia marenzelleri La Rue 1911 :481 



Specific Diagnosis: Characters of genus. Observed length of stro- 

 bila as much as 40 cm. Maximum breadth 1.5-2.0 mm. Scolex large, 

 round, muscular, 1.2-2.0 mm. broad, well set off from neck. No rostel- 

 lum. No hooks. No functional fifth sucker. Suckers four, 0.60-0.70 

 mm. in diameter. Neck not observed. Strobilation distinct. Proglot- 

 tids closely attached. Length of proglottids as much as 5.5 mm., maxi- 

 mum breadth of same 1.5-2.0 mm. Excretory system composed of two 

 pairs of lateral vessels. Genital organs as in genus. Genital aperture 

 marginal, irregularly alternating, situated near middle of lateral mar- 

 gin of proglottid. Testes numbering 150-200-240, measuring 0.06-0.07 

 mm. in diameter, situated in two lateral fields. Cirrus-pouch large, 

 extending about one-third across the proglottid breadth. Cirrus, when 

 protruded, swollen at base and filiform at tip, 1 mm. long. Vagina 

 usually posterior to cirrus-pouch. Uterus when completely developed 

 possessing 20-25 lateral outpocketings on either side. Eggs provided 

 with two membranes. Diameter not known. 



Habitat: In intestine of Ancistrodon piscivorous Holbr., southern 

 United States. 



Barrois (1898) in a very brief description, unaccompanied by 

 drawings, proposed this species. Schwarz (1908:26-27) redescribed 

 this species using Barrois 's material. His description was accompanied 

 by three drawings. La Rue (1911:481) included this species in the 

 new genus Ophiotaenia. 



The material which Barrois and Schwarz had for study was col- 

 lected by Doctor Calmette, Dec. 22, 1897, from Ancistrodon piscivorous 

 Holbr., a snake indigenous to the southern United States. Unfortu- 

 nately specimens of this species could not be had by the writer for 

 study hence the data used in the following description are derived only 

 from the articles of Barrois (1898) and Schwarz (1908). A study of 



