ECHINOTHKIX CALAMARIS. 117 



Echinothrix calamaris A. Ag. 



Echinus calamaris Pallas, 1774. Spic. Zool., I, fasc. 10, p. 31. 

 Echinothrix calamaris A. Agassiz, 1872. lie v. Ech., Ft. I, p. 119. 



This species was taken by the " Albatross " at the following stations : 



Puako Bay, Hawaii, Hawaiian Islands. 



Station 4033. Penguin Bank, S. coast of Oahu, H. I. 28-29 fathoms. 

 Fne. CO. s. for. 

 Two specimens. 



Centrostephanus. 



Peters, 1855. Deiik. Akad. Berlin fiir 1854, p. 109. 

 Type-species, Diadema longispina Philippi, 1845. Arch. f. Naturg. XI (1), p. 354. 



The species of this genus are remarkable not only for the fact that they are 

 so easily recognized, — synonyms are almost unknown among them, — but 

 also for the presence of peculiar glandular, globiferous pedicellarias, and for 

 their geographical distribution. Unlike all the other genera of Diadematidse, 

 Centrostephanus is unknown from the Indo-Pacific region, nor does it occur in 

 tlie West Indies, and yet the four species are widely separated from each other. 

 One species, longispimis Phil., occurs in the Mediterranean and eastern Atlantic, 

 a second, coronatus Verr., is found on the west coast of Mexico, a third, 

 astenscus A. Ag. and CI., is known only from the Hawaiian Islands, while the 

 fourth, Rodgersii A. Ag., inhabits the coasts of Australia, Lord Howe Island, 

 and Tasmania. All are strictly littoral. These species are easily distin- 

 guished from each other by the coloration, which appears to be unusually 

 constant. They may be recognized by the following characters : 



Primary spines unicolor, deep reddish-purple (lighter in very small speci- 

 mens, and with faint indications of bands) ; size large, up to 100 mm. 



h. d. or more Rodcjersii. 



Primary spines banded with two colors or shades; size small, rarely exceed- 

 ing 40 mm. h. d. 



No whitish markings on abactinal part of test ; spines banded with light 



and dark reddish or reddish-brown coronatus. 



Conspicuous whitish lines present on abactinal part of test; spines 

 banded in two colors. 



Whitish lines present in middle of each ambulacrum and inter- 

 ambulacrum, and along margin of each ambulacrum, abactinally ; 



spines banded with light yellowish-green and purplish longispinus. 



Whitish lines run only from centre of anal system to upper end of 

 each ambulacrum, thus forming an abactinal star; spines banded 

 with deep red and white asteriscics. 



