1911] Watson: The Genus Gyrocotyle. 363 



(Gr. et Wag.) (from Chimaera monstrosa) and G. rugosa Diesing 

 (from Callorhynchus antarcticus) , but adds (p. 1157) that they 

 "differiren so wenig von einander, dass es fraglich 1st, ob die 

 Unterscheidung zweier Species sich rechtfertigen lasst^ moglich- 

 erweise bestehen Unterscheide in der Lage der Genitalpori. " 

 According to Lonnberg and Wagener, the vaginal opening is the 

 most anterior and lateral to the penis ; but according to Spencer, 

 dealing with G. rugosa, the penis opening is anterior to the 

 vagina and marginal. 



Benham (1891) recognized the single genus, Gyrocotyle, "in 

 the intestine of Chimaera and Callorhynchus." 



Haswell (1902) reported a new species of Gyrocotyle, G. 

 nigrosetosa, from a new species of Chimaera, C. ogilbyi, trawled 

 off the Australian coast by the "Thetis." Haswell had one 

 specimen of G. rugosa, and two specimens of the new species, 

 "not in good condition for investigation." He did not study 

 the living form. He distinguishes G. rugosa from G. urna (fol- 

 lowing Lonnberg 's description of the latter) on the following 

 grounds : 



(1) Relative positions of the apertures of the penis and 

 vagina. 



(2) Presence of an eversible cirrus, adapted to self -impreg- 

 nation, in G. rugosa. 



(3) Spinules lining ejaculatory duct, in G. urna. 



(4) Size of eggs. 



(5) Presence of hexacanth embryo in G. rugosa. 



(6) Shape of spines, which are simpler in G. rugosa. 



C. GYROCOTYLE OF THE COAST OF CALIFORNIA. 



I. OCCURENCE AND HOST. 



As this review of the literature shows, the genus Gyrocotyle 

 includes three species, G. rugosa, G. urna, and G. nigrosetosa^ 

 all occuring as intestinal parasites in the family Chimaeridae. 

 The occurrence of a form of the genus in Chimaera colliei, found 

 off the coast of California, has not to my knowledge been previ- 

 ously reported. So far as can be determined, no work has ever 

 been done on the parasites of C. colliei. This is the only species 



