580 



complicate matters; the furms which must be taken iiitu con- 

 sideration are Taenia polymorpha Kudolphi, 1819, pars (as de- 

 termined by Krabbe 1869, p. 301) from Recurvirostra avocetta 

 and "Taenia lavis Bloch (Diesing)" (see Krabbe, 1869, p. 302), 

 from Aythya ferina (Fuligula ferina). 



In deference to my Italian colleague Diamare, I adopt his 

 genera provisiionally, postponing final opinion in regard to them 

 until his more detailed publication appears. 



a. Two s\ilmiedlan ovaries in each .seKiiieiit. 



a'. Hooks on rostelluni arranged In several rows. 



Genus DIPYLIOIUM K. Leuckart, 1863.1 



(1858, Alyselminthus Zeder, 1800, partim Weinland.) 



Diagnosis: Rostellum retractile, armed with several trans- 

 verse rows of alternating hooks; hooks with small roots, the 

 base being discoidal; mature segments elongate with double 

 sets of genital opgans; pores double and op'posite; testicles very 

 numerous, scattered through the median field; ovary bilobled; 

 vitellogene glands distal; uterus at first reticulate among the 

 testicles, finally resolving itself into independent egg sacs con- 

 taining one or several ova; ova with double transparent mem- 

 branes. Typ^e species: D. caninum (Linne, 1767). 



No members of this genus have as yet been recorded 

 from birds. The type species D. caninum inhabits thi' 

 intestine of dogs, cats, and man; its larval stage lives 

 in fleas (Pulex seri'aticeps P. irritans) and lice fTricho- 

 dectes canis). 



a'. Hooks on head arranged in a single row. 



Genns COrtJGNIA Diamare, 18M. (Gen. Inq.). 



Diagnosis: Head large, with a rudimentary retractile rostel- 

 lum armed with a large number of very minute booklets ar- 

 ranged in a single row. prong thick and short, without dorsal 

 root, with ventral root thin and elongate toiward the point. 

 Suckers large and unarmed. Mature segments broader than 



iFor full ijihliography consult Damare's monograph (1893) II 

 Oenere Dipylidium I^kt. < Atti. R. Accad. Scienze fische e 

 matrmatiche. Vol. VI. ser. 2a, No. 7. 31 pages, 3 plates. Care 

 should, however, be exercised in accepting the dates given by 

 Diamare as many typographical eirors ha\e crept intu the 

 bibliogrnphy. 



