106 BULLETIN 69, UNITED STATES NATIONAL MUSEUM. 



GENERA IMPERFECTLY KNOWN. 

 Genus TETRACISDICOTYLA Fuhrmann, 1907. 



Generic diagnosis. — Tsenioidea: Scolex relatively large, without 

 rostellum. In the posterior portion of each sucker a peculiar muscular 

 organ simulating a pair of smaller suckers. Neck absent. Segmen- 

 tation of the strobila indistinct. A single set of reproductive organs 

 in each segment. Genital pores marginal, irregularly alternating. 

 Cirrus pouch large. Vas deferens coiled. Testicles numerous. 

 Vagina opens into the genital pore in front of cirrus pouch. Adults 

 in birds. 



Type-sj^ecies. — Tetracisdicotyla macroscolecina Fuhrmann, 1907. 



TETRACISDICOTYLA MACROSCOLECINA Fuhrmann, 1907. 

 For description see Fuhrmann, 1907b, pp. 535-536, fig. 43. 



Host. — Butorides virescens. 



Genus COPESOMA Sinitsin, 1896. 



Generic diagnosis. — Tsenioidea: Scolex with large rostellum. Gen- 

 ital pores irregularly alternate, in young segments ventral, in gravid 

 segments marginal. Adults in birds. 



TypesiJecies. — Copesoma papillosuTn Sinitsin, 1896. 



COPESOMA PAPILLOSUM Sinitsin, 1896. 



For description see Fuhrmann, 1901a, p. 761. 



Host. — fPisohia damacensis. 



IMPERFECTLY KNOWN SPECIES. 



T.ffi;NIA COLLICULORUM Krabbe, 1869. 



For description see Krabbe, 1869b, p. 330, pL 9, fig. 259. 



Host. — Riparia riparia. 



T.ffi:NIA CONICA" Molin, 1858. 



For description see Molin, 1861c, pp. 253-254, pi. 7, figs.l, 2.— Stiles, 1896f, 

 pi. 3, figs. 35, 36. 



Host. — Anas platyrhyncTios. 



T.ffiNIA DISTINCTA Lonnberg, 1889. 



For description see Lonnberg, 1889a, pp. 12-13, .figs. 3, 4. 

 Host.--Larus canus. 



TJENIA FILUM " Goeze of Linton, 1892. 



For description see Linton, 18921, pp. 106-107, pi. 8, figs. 72-78. 

 Host. — Larus calif ornicus. 



o- Part of Molin's original (Bureau of Animal Industry, No. 1390) shows the long, 

 prominent rostellum, with marks indicating that at one time there were 10 hooks 

 present. 



b According to Fuhrmann (1908a, p. 126) this form is probably a Hymenolepis, possi- 

 bly H.fusus. 



