100 s. GOTO 



" Udbredelse : Circumpolar. I 

 Atlaiiterhavet gaar den mod Syd til 

 Fscr0-Kanalen og til Kap Cod paa 

 Nord- Amerikas Ostkyst ; i Stilloliavet 

 til det Japanske-Hav og längs liele 

 Amerikas Vestkj-st til Magellansti*a3- 

 de {Gtenodiscus procurator Sladen) ; 

 ogsaa ved Syd- Amerikas Ostkyst (Cte- 

 nodiscus australis Lütken). 



" Distribution : Circumpolar. In 

 the Atlantic Ocean it goes towards 

 the south to the Faîroë Canal and to 

 Cape Cod on the east coast of North 

 America ; in the Pacific Ocean to 

 the Japan Sea and along the whole 

 west coast of America to the Strait 

 of Magellan {Ctenodiscus 2>i'Ocurator 

 Sladen) ; also on the east coast of 

 South America [Ctenodiscus cmstralis 

 Lütken). 



That the Ctenodiseus hrausel of Ludwig is probably identical 

 with C. crispatus has been suggested by Döderlein and admitted 

 by Ludwig liimself. The principal points of difference which, led 

 the last mentioned authority to make a new species for his 

 specimens from the Bering Sea was the absence of a skeletal 

 reticulum in the dorsal wall of the disk, the greater number of 

 spinelets on either side of the keel of the superomarginal plates, 

 and the presence of skin folds containing small flattened calca- 

 reous rods behind the row of lateral spinelets just mentioned. A 

 dorsal skeletal reticulum has been described as being present in 

 Ct. crispatus by Duncan and Sladen ; but an examination of a 

 couple of specimens of this species from Casco Bay, Maine, has 

 shown beyond doubt that no such reticulum is present, the bases 

 of the paxillœ expanding somewhat but remaining entirely separate 

 from one another. As to the presence of longitudinal skin folds 

 in the fasciolar grooves of the marginal plates, they are very well 

 developed in all the specimens of Ct. crispatus examined by me, 

 while the number of the lateral spinelets on the keel of the 

 superomarginal plates is subject to much variation. It appears 

 then that one is completely justified in regarding Ct. hrausei as 

 a synonym of Ct. crispatus. 



