246 ILLINOIS BIOLOGICAL MONOGRAPHS [246 



differs from Crepidobothrium gerrardii (Baird) in the size of the head 

 and suckers, and in the character of the latter. 0. grandis has a long 

 unsegmented neck while C. gerrardii has almost no neck. 0. grandis 

 somewhat resembles 0. calmettei in the size of the head and suckers. It 

 differs from that species in the size of strobila and of proglottids, and 

 in length of neck. 0. grandis has a larger number of testes and a cirrus 

 which differs greatly from that of 6. calmettei. 0. grandis is so much 

 larger than 0. perspicua, 0. nattereri (Parona), 0. trimeresuri (Parona), 

 and 0. racemosa (Rudolphi) that a possibility of confusing it with any 

 of those species is precluded. 



CREPIDOBOTHRIUM GERRARDII (Baird) 



[Figs. 12, 13, 33, 34, 42, 111-115, 123, 124, 190, 196] 



1850: Taenia racemosa 



1860: Tetrabothrium gerrardii 



1861: Tetrabothrium gerrardii 



1864: Tetrabothrium gerrardii 



1898: Ichthyotaenia gerrardii 



1899 : Crepidobothrium gerrardii 



1899 : Ichthyotaenia gerrardii 



1905 : Taenia, racemosa 



1908 : Taenia eunectes 



1911 : Crepidobothrium gerrardii La Rue 1911 :479-480 



Specific Diagnosis: Characters of genus. Length of strobila as 

 much as 45.6 cm. Maximum breadth 0.85-2.00 and even 6.0 mm. Stro- 

 bila flat, thin and wrinkled. Proglottids closely attached. Segmentation 

 indistinct. Head large, tetragonal, pyramidal, maximum breadth of 

 same 0.935-1.3 or even as much as 1.75 mm., thickness a little less than 

 breadth, length about 0.68-0.90 mm. Fifth sucker vestigial but with 

 cavity open to exterior. Four suckers prominent, muscular, cordate, 

 with lower margin interrupted and re-entrant into sucker cavity. 

 Breadth of suckers 0.40-0.70 mm. Neck broad, not over 0.5-0.8 mm. 

 long. First proglottids short, rapidly increasing in length. Mature 

 proglottids quadrate. Ripe proglottids longer than broad. Length of 

 same 1.7-2.3 mm. by 0.65-1.09 mm. broad. 



Genital pore marginal, irregularly alternating, situated near mid- 

 dle of proglottid. Vagina anterior or posterior to cirrus-pouch. Open- 

 ing of vagina dorsal to cirrus-pouch. Testes 200-400 in number, small, 

 0.035-0.050-0.080 mm. in diameter, situated in two lateral fields. Cirrus- 



