PARASITIC FLATWORMS 439 



51 (50) Testes number 150 to 215. Ophiotaenia perspicua La Rue 1911. 



Length up to 360 mm., maximum breadth 

 about 2.0 mm. First proglottids short, mature 

 proglottids quadrate (2.0 mm.) or somewhat longer 

 than broad, ripe proglottids as much as 3.8 mm. 

 long by 1.2 mm. broad. 



Genital pore situated near middle or at end of 

 first third of proglottid. Testes rso to 215. Vas 

 deferens in ripe proglottids heavy mass of coils 

 reaching from end of cirrus-pouch to mid-field. 

 Ratio of length of cirrus-pouch to proglottid 

 breadth i : 4 to 1:3. Vagina anterior or pos- 

 terior to but not crossing cirrus-pouch. Uterus 

 with 20 to 30 lateral pouches on each side. 



Habitat: Natrix(Nerodia) cAojuii/er Hallowell; 

 Illinois, Oklahoma. 



Fig. 742. Ophiotaenia perspicua. a. Head, X 23: 

 h, ripe proglottid, showing uterine poucues, and testes. 

 (After La Rue.) 



52 (49) Genital pore at or near center of margin of proglottid. 



Ophiotaenia grandis La Rue 191 1. 



Very long (fragments 200 mm.), 2.7s to 4.25 

 mm. broad in ripe proglottids. First proglottids 

 muchbroader than long; proglottids with develop- 

 ing sexual organs quadrate or nearly so; ripe pro- 

 glottids quadrate or much longer than broad. 

 Head large, i.o to 1.2 mm. broad at base of suck- 

 ers. Suckers about 0.34 by 0.36 mm. Testes 

 large, numerous, 200 to 250. Cirrus-pouch 0.24 to 

 0.26 mm. broad, 0.64 to 0.75 mm. long, enclosing 

 few or no coils of ductus ejaculatorius. Uterus 

 with 40 to 60 lateral outpocketings on each side. 



In intestine of Ancistrodon pisciwrus Holbr., 

 locaUty not known. 



Fig. 743. Ophiotaenia grandis. a, Head, showing 

 swollen region back of head, X 8; 6, mature pro- 

 glottid, ventral view showing reproductive organs and 

 ventral uterine pores (m/ii^). X id. (After La Rue.) 



53 (32) Many lappets or folds of tissue about suckers. 



Comllobothrium Fritsch 1886. 



Scolex with four suckers situated on the flat anterior face of the head. Many irregular 

 folds and lappets of tissue about margin of anterior surface; may enclose suckers as in a corolla. 

 No rostellum. No hooks nor spines. Neck broad, short. Habitat: In Siluridae. 



Marshall and GUbert report the occurrence of two species in the common bullhead. I have 

 an undescribed species taken from a channel-cat at Milford, Neb. 



54 (31) Vitellaria condensed, in a single mass, in medullary layer, usually 



immediately posterior to ovary, rarely anterior to it. 



Order Cyclophyllidea . . 55 



Scolex with 4 cup or saucer-shaped suckers and in the center an apical organ or rostellum of 

 varied form. Hooks common on rostellum, very rare on suckers. Segmentation well devel- 

 oped, only rarely absent (Fimbriariidae); proglottids set free after full maturity. No uterine 

 pore; rarely a secondary connection to the exterior permits the escape of ova. Testes in medul- 

 lary layer, ordinarily numerous. Ovary bilobed; vitellarium compact, single, near ovary 



