172 



ILLINOIS BIOLOGICAL MONOGRAPHS 



ABOTHRIUM RUGOSUM (Batsch 1786) 

 [Figs. 32-36, 63, 76, 91, 109] 



[460 



Specific diagnosis: With the characters of the genus. Large cestodes 

 with maximum length, breadth and thickness of 1000, 7 and 2inm., respectively. 

 Scolex present only in very young strobilas, when conical and provided with 

 very weak bothria, changing with age to a pseudoscolex of various shapes, 

 usually imbedded in pyloric cecum of host. Proglottides at first broad and 

 ver>' short, obscured by irregular transverse and longitudinal rugae, then 

 gradually lengthening with age until finally quadrate or longer than broad, 



Cuticula 5m thick, subcuticula 0.14mm. Small calcareous bodies, 20ju in 

 length. Longitudinal muscles in bundles, transverse forming septa between 

 proglottides. Nerve strands 45^1 in diameter. Two chief excretory vessels 

 anteriorly, passing into 30 to 35 posteriorly. 



Genital cloaca irregularly alternating, between first and second thirds of 

 edges of proglottides. Vagina opens immediately behind the cirrus and 

 slightly ventral; no hermaphroditic duct. 



