Boone, Echinodermata, Cruises of "Ara" and "Alva" 149 



DiSTRffiUTlON : This species is widely distributed in the Httoral 

 zone of the Indo-Pacific from the Red Sea (Ljungman, von Mar- 

 tens, Koehler) ; southward to East Africa (von Martens) ; Zanzi- 

 bar (Koehler) ; Madagascar (Hoffman) ; He de France (Muller 

 and Troschel) ; Mauritius (Michelin, de Loriol, Mobius, Koehler) ; 

 Mascarenes (von Martens) ; and eastward to Ceylon (Bell, 

 Walther) ; China Sea, off southern Luzon, 12-13 fathoms (Koeh- 

 ler) ; Sunda Isles: Java (Ljungman, Koehler, H. L. Clark); 

 Borneo Bank, Karkaralong, Kur Isle, entrance to Nusa Besi and 

 Saman Isle (Koehler) ; Amboina (Brock) ; coral reefs, Timor 

 (Studer) ; Torres Straits, Murray Islands, Mer (H. L. Clark) ; 

 Ternate (Lyman) ; China Straits, New Britain (Bell) ; Kings- 

 mill or Gilbert Islands (Lyman, Ljungman, Clark) ; Sandwich 

 Islands (Lyman) ; Honolulu Harbor, Maui, Hilo, Hawaiian 

 Islands, Pearl and Hermes Reef, Laysan Island, Ocean Island, 

 Wake Island, Johnston Island (Clark) ; Honolulu Harbor, Oahu 

 (Boone) ; Society Islands (Ljungman, Clark). 



Material examined: Four specim.ens from Pearl Harbor, 

 Oahu, Hawaiian Islands. Twenty-one specimens, Kaneohe Bay, 

 Oahu, 2 fathoms low tide, December, 1928, collected by the "Ara." 



Technical description: TTie disk diameter of the largest 

 specimen is 20 millimeters, total arm length 50 millimeters, of the 

 second specimen 15 millimeters disk diameter and 27 millimeters 

 arm length, of the third specimen, 13 millimeters disk diameter, 

 24 millimeters arm length, of the fourth specimen, 8 millimeters 

 disk diameter and 18 millimeters arm length, thus showing a vari- 

 ation of arm length of from twice to two and a half times the 

 related disk diameter, in the Pearl Harbor series. 



The disk is circular in contour, moderately thick, with the 

 abactinal and actinal surfaces of the interbrachial regions cov- 

 ered with coarse, rounded granules which form a continuous pave- 

 ment. The mouth shield is an elaborate lozenze shape, with the 

 inner margin truncate and nearly twice as broad as the opposite 

 outer narrowed margin and the paired inner lateral margins 

 oblique and slightly longer than the related paired outer lateral 

 margins. The paired side mouth shields are triangulate fitting 

 closely around the margins of the central mouth shield, the apices 

 of the side mouth shields lying adjacent, on either side, to the 

 distal lateral angle of the mouth shield and being separated from 



