558 



THE VOYAGE OF H.M.S. CHALLENGER. 



ft. Bathy metrical range: 14 to 1808 fathoms. 



Greatest range of one species : Pedicellaster typicus, 50 to 620 fathoms. 

 Of the other species Pedicellaster margaritaceus and Pedicellaster sex- 



radiatus only occur in the Abyssal zone. The remainder inhabit the Littoral 



zone, and are not recorded from greater depths, excepting Pedicellaster 



pourtalesi, which extends into the Continental zone. 

 y. Nature of the Sea-bottom : Pedicellaster typicus is found on Clay (sometimes 



sandy) and Stones ; Pedicellaster palxocrystallus on a hard bottom ; 



Pedicellaster pourtalesi on fine sand ; Pedicellaster scaber on Volcanic mud ; 



and Pedicellaster hypernotius on Volcanic sand. 

 The species collected by the Challenger are indicated in the above list by an asterisk. 



Chorological Synopsis of the Species. 



1. Pedicellaster scaber, Smith. 



Pedicellaster scaber, Smith, 1876, Ann. and Mag. Nat. Hist., ser. 4, vol. xvii. p. 107 ; Phil. Trans., 

 Zool. Kerguelen Island, 1S79, vol. clxviii. p. 274, pi. xvi. fig. 3. 



Locality. — Station 149d. Royal Sound, Kerguelen Island. January 20, 1874. Lat. 

 49° 28' 0" S., long. 70° 13' 0" E. Depth 20 to 25 fathoms. Volcanic mud. Surface 

 temperature 41 o- Fahr. 



Remarks. — This is a well-marked species, and is not merely a variety of Pedicellaster 

 typicus, as suggested by Danielssen and Koren. 1 



2. Pedicellaster hypemotius, n. sp. (PI. CV. figs. 5-7). 



Rays five. R = 25 mm. ; r= 5 mm. R = 5 r. Breadth of a ray at the base 5*25 mm. 



Rays elongate, narrow, tapering very slightly ; probably subcylindrical during life, 

 more or less depressed in their present condition. Disk small, not distinguishable from 

 the base of the rays. Interbrachial arcs acute. 



1 Nyt Mag.f. Naturvidensk., Bd. xxvii. p. 274; Den Norske Nordhavs-Expedition, 1876-1878. Zoologi, 

 xi. Asteroidea, Christiania, 1884, p. 40. 



