382 University of California Publications in Zoology. [VOL. 6 



V. KEY TO SPECIES OF GYBOCOTYLE. 



On the basis of the above discussion, the following classifica- 

 tion is proposed : 



A. Frills of posterior rosette simple. 



I. Uterine eggs containing hooked embryos. Opening of penis 



laterad of, and anterior to, vaginal opening. 



G. rugosa. 



Host: Mactra edulis. Diesing (1850, p. 408) Brazil. Mon- 

 ticelli (1889b, p. 228). 



Callorhyncus antarcticus. Monticelli (1889c, p. 327), 

 Dunedin, N. Z. Spencer (1889, p. 138), Australia. 



II. Uterine eggs not containing hooked embryos. Opening of penis 

 mediad to vaginal opening. 



(1) Opening of penis posterior to vaginal opening. 



(a) Eggs without operculum. 



G. urna. 



Host: Chimaera monstrosa. Wagener (1852, p. 545). Nice. 

 Kroyer, I)anmark's Fiske, v. 3, p. 813. Van Beneden 

 and Hesse (1864, p. 54). Olsson (1868, p. 58; 1896, p. 

 508). Lonnberg (1891, p. 14). Bergen, Christiania. 

 Monticelli (1889b, p. 229; 1889b, p. 327). Mediterranean. 

 Hansson. Free-living off the west coast of Sweden. 

 (Lonnberg, 1891, p. 14). 



(b) Eggs with operculum. 



G. nigrosetosa. 



Host: Chimaera ogilbyi, Haswell (1902, p. 48). Australia. 



(2) Opening of penis at the same level as vaginal opening. 

 G. urna (var?) 



Host: Chimaera colliei, from the California coast. Has 

 been found attached by terminal rosette to mucosa of 

 spiral valve. 



B. Frills of posterior rosette complex. Opening of penis mediad to 

 vaginal opening, at same level. 



G. fimbriata. 



Host: Chimaera colliei: off the California coast. Has been 

 found attached as above, free in intestine, and in mouth 

 and on gills of host. 



