54 



ILLINOIS BIOLOGICAL MONOGRAPHS 



342] 



funnel-shaped, 0.3 to 0.6mm. long and 0.5 to 0.9 broad, with revolute edges. 

 Neck 1.0 to 1.8mm. in length. Segments twice as broad as long, terminal one 

 rounded. 



Cuticula 5 to 6/i in thickness, with neither hooks nor spines; subcuticula 

 25 to 50/x. 



Ten to twenty sets of genitalia, beginning 1.5 to 2.0mm. from the anterior 

 end. Strong tendency for the reproductive apertures to lie all on one surface 

 of the strobila. Vagina opens behind the uterus. Neither papillae nor 

 sphincters around the genital openings. 



Testes in two lateral fields in the medulla of the anterior portion of the 

 proglottis, 60 to IQix in diameter. Coiled vas deferens anterodorsal to cirrus- 

 sac; no seminal vesicle before entering cirrus-sac nor connective tissue sack 

 surrounding the whole duct. Protruded cirrus 0.2mm. in length by 0.12 in 

 diameter at base. Cirrus-sac ovoid in shape 0.20 to 0.23mm. in length by 0.17 

 in diameter; no retractors connecting it with the dorsal body- wall; large mass 

 of glandular pigmented cells surrounding it dorsally and laterally. 



Vagina 12 to 15m in diameter; no sheath near its opening; receptaculum 

 seminis 50 to 75/x. Spermiduct very short and narrow, 25 and 8/i respectively. 

 Ovary tubulolobular, fan-shaped; wings extending dorsally and laterally around 

 the ventral genital ducts; isthmus prominent, 0.18 by 0.10mm.; ova in same 

 13 to 15/x in diameter. Oocapt 25/x in diameter. Vitelline follicles continuous 

 from proglottis to proglottis, forming a layer 90/i thick in the cortical paren- 

 Chjmtia, 20 to 35 in transections. Shell-gland dorsal. Uterine rosette not 

 surrounded by a muscular sac, but the organ is enveloped proximally by 

 nimierous glandular cells. 



Eggs, 40 by 30/1. 



Habitat: In stomach, pyloric ceca and intestine of the host. 



Type specimen: No. 165A, in the writer's collection. 



Co-type: No. 165B, in the collection of the University of Illinois. 



Type locality: Georgian Bay, Lake Huron, off Giant's Tomb Island. 



Altho the species described here is closely related to C. truncatus of Europe, 

 it presents so many differences from that species, even barring some probable 

 errors by Kraemer (1892), that it is considered to be new. Probably the same 

 form was reported by Linton (1898:428). 



