NO. 1105. PBOCEEBINGS OF THE NATIONAL MUSEUM. ' 217 



lateral canals ; trari averse utenis single willi proximal and distal pouches ; dorsal 

 canal hettveen ventral canal and nerve; strobila may attain 112 mm. long by 5 to 13 

 mm. broad. Host: Marmot {krctovaysmaxn\ot&), Europe. C. marmoiw ( -p. 172). 



22. CirrUvS pouch A'ery large and jji-ominent, niaj^ attain 1.12 mm. long by 0.32 mm. 



broad ; ])ore8 at or near distal corner of lateral margin ; female glands not far 

 removed from dorsal canal; several accessory ventral canals; strobila may 

 attain 80 cm. long by 15 mm. broad. Host: Wild rabbit (Lepus cuniculus), 



Europe C. deniiculata (p. 174), 



Cirrus pouch siiiaU, (i..'4 mm. long; female glands considerably r'emored from dorsal 

 canal; dorsal canal lateral or dorso-lateral of ventral canal ; receptaculnm seminis 

 very large; segments imbricate; strobila attains 40 mm. long by 5.5 mm. broad. 

 Ho.'>t: Prairie gopher (Ueomys bursarius), North America.. C. pra'coqnis (p. 181). 



23. Cirrus pouch about 1 mm. long, exten()s some distance median of longitudinal 



canals; testicles arranged in a band iu distal portion of median field, extend- 

 ing beyond ovaries from canal to canal; ovary some distance from longitudi- 

 nal canals; uterus single, with Avell-developed proximal and distal pouches; 

 strobila attains 40 cm. in length by 8 to 10 mm. in breadth. Hosts: Common 

 hare (Lepus timidus) and mountain hare (L. variabilis) Eui'ope. 



C. peclinaia (p. 184). 



Cirrus pouch not over 0.5 nnn. long, extends scarcely median of lateral canals; 



uterus single ordouble in the same strobila. Hosts: Lepus, North America. 24 



24. Testicles in two groups, one for eacli ovary, extending laterally of ovaries but 



absent from median field ; strobila attains 57 mm. or more in length by 10 mm. 



in breadth. Host: Cottontail rabb-it (/>. .s'(///-«/(c».s) C. perjylcxa (p. IS9). 



Testicles in a band confined to distal portion of median Held between the 

 ovaries; strobila attains 100 to 180 mm. in length by 10 mm. iu breadth. 

 Host: Cottontail rabbit (L. sylraficus) and marsh hare ( L. palnstris). 



C. rariahilis (p. 190), 25. 



25. Strobila nearly always more than 3 nun. broad; posterior fiap of segments 



nearly straight; segments slightly imbricate: genital pore in about the 

 middle of the lateral margin. Host: Cottontail rahhit (L. sylvaiicus). 



C. rariabilis(l^. 192), 



Strobila nearly always more than 3 mm. broad; posterior flap of segments 

 lobed; segments imbricate; genital pores generally in distal half of lateral 

 margin. Host: Marsh hare (L. jjalustris) C. variabilis imbricata (p. 193), 



Strobila rarely over 2 mm. broad; posterior flap straight; segments not imbri- 

 cate; genital pores generally in distal portion of lateral margin, generally 

 double, occasionally single. Host: Cottontail rabbit {L. sylralicus). 



C. variabilis angusta (p. 193). 

 Andrya (European). 



26. Genital pores near posterior corner of segment; prostatic gland elongate; head 



about 1 mm. iu diameter; testicles comparatively few in number, confined 

 chiefly to aporose side of median field; cirrus pouch 0.32 to 0.34 mm. long; 

 strobila attains 60 to 80 cm. in length by 5 mm. in breadth. Host: Common 



hare (Lepus limidun), Europe A. rhopalocephala (p. 155). 



Genitnl p(n-es in about the middle, or in the distal half of the lateral margin; 

 prostatic gland round; liead about 0.5 mm. iu diameter; testicles about 50 in 

 number, scattered through entire median fi.eld: cirrus pouch 0.4 to 0.18 mm. 

 long; strobila attains 100 cm. in length by 8 mm. in breadth. Host: Wild 

 rabbit (Lepus cuniculus), Eurojie A. cunicuU (p. 158). 



Dipylidiina'. 



27. Suckers unarmed 28 



Suckers armed with minute hooklets (with four exceptions known only in 



birds) 33 



28. (ienital pores double 29 



Genital pores single, irregularly alternate or unilateral 31 



