ECHINOIDEA. II. 



Sch. fragilis, and even more the quite similar development of the fascicles in Abatus cavernosus, where 

 both lateral and anal fascicle generally disappear with age, shows that the latero-anal fascicle is part 

 of the primary fascicle. 



Sch. fragilis was taken by the Ingolf-Expedition at the following stations: 



St. 25 (63 20' Lat. N. 54 25' Long. W. 582 fathoms 33 C. Bottom temp.) 5 specimens. 



) 10 

 ) Numerous specimens. 



) 35 



- ) 5 



- ) i 



- ) 2 



) I 



) 4 



- ) 2 



The species was further taken in the Davis Strait by Wan del 1889 (63 56' Lat. N. 53 12' 

 Long. W. 130 fathoms, i specimen). Several specimens were taken at the Faroe Islands (150 190 

 fathoms) by the author in 1899 and by Ad. S. Jensen (Michael Sars. 1902). 



The bathymetrical distribution of this species is ca. 35 700 fathoms. In the Challenger- 

 Echinoidea, p. 221 it is stated to have been taken (by the Blake) at a depth of 955 fathoms at the 

 Caribbean Islands*. I cannot find in the Preliminary Report on the Blake-Echini (Bull. Mus. Comp. 

 Zool. VIII. 1880. Nr. 2. p. 84) or in Professor Rathbuii's works any locality to which this statement 

 might refer. The geographical distribution of Sch. fragilis is: from the Northern Norway to the 

 Faroe Channel, South of Iceland, Davis Strait and along the American coast down to Florida. On the 

 European side of the Atlantic it is not known farther south than the Faroe Channel, and it is not 

 known from the Mediterranean or the Azores. 



Sars (loc. cit.) and recently Grieg (loc. cit.) point out that Sch. fragilis is both more common 

 and reaches a considerably larger size at Northern Norway than farther South ; thus it reaches a 

 size of 90""" length at the Northern Coasts, whereas the largest specimens known from Bergen are 

 only 55""". (A specimen from the Faroe Islands has the same size, and a specimen from the American 

 Coast (S. of Long Island, 302 fathoms) is 6o mm in length). It is therefore without doubt to be regarded 

 as an arctic form. It is certainly a remarkable fact that the largest specimens are from the most 

 northern locality, but nevertheless Sch. fragilis is evidently no arctic form. It is not found in the cold 

 area of the Norwegian Sea, occurring only where the bottom temperature is positive. It is one of 

 thpse rather numerous species, which belong to the Northern Atlantic, the warm area, but, on account 

 of the peculiar hydrography of the Norwegian Sea, proceed far North along the Norwegian Coast 



In the Challenger -Echinoidea (p. 201 2) Sch. fragilis is recorded from the Cape of Good 

 Hope, and recently Professor Bell 1 likewise records the species from South of Africa. Doderlein 

 (Op. cit. p. 250) supposes that these specimens are really Sch. capensis Studer, of which species a careful 

 description and figures are given. Having myself examined the type specimen of the Sch. capensis in 



1 The Echinoderma found off the Coast of South Africa. I. Echinoidea. Marine Investigations in South Africa. III. 

 1904. p. 175. 



15* 



