250 BULLETIN 82, UNITED STATES NATIONAL MUSEUM 



border deeply bowed proximally in the form of a broadly rounded angle deeply 

 incising the IBri. 



The 10 arms are 20 mm. long. The first brachials are about 5 times as broad as 

 long in the median line; their distal edge is parallel to the proximal from the inner 

 side as far as the midradial line, then turns and runs diagonally upward and outward 

 so that the outer side is twice as long as the inner, or even longer. The first brachials 

 are separated interiorly for about half their length, or rather less, by a V-shaped gap of 

 moderate width. The second brachials are larger than the first and are UTegularly 

 quadrate. The first syzygial pair (composed of brachials 3 + 4) is slightly longer 

 interiorly than exteriorly, as long as, or slightly longer than, broad exteriorly, with 

 the hjTJOzygal somewhat larger than the oblong epizygal. The next two brachials 

 are roughly oblong, broader than long, and those following are very obliquely wedge- 

 shaped, longer than broad, becoming elongated and centrally constricted in the outer 

 portions of the arms. The division series and brachials are densely clothed with an 

 exceedingly fine spinulation. Syzygies occur between brachials 3+4, 9 + 10, and 

 14 + 15, and distally at intervals of 3 muscular articulations. 



Pi and Pa are absent. P2 (on the fifth brachial) is 2.3 mm. long, stiffened, with 

 8 segments of which the first is slightly broader than long, the second is between half 

 again and twice as long as broad, the third is four times as long as broad, and the 

 remainder are greatly elongated, except for the terminal, which is about half the length 

 of that preceding and ends in a few long spines. The long segments have slightly 

 concave sides, and the distal ends on the side toward the arm tip are armed with 

 several rather long spines. P3 is similar, with 8 segments, and Pb and Po are also 

 similar. The pinnules following are shorter and flexible, and carry gonads. 



The color in alcohol is yellowish white blotched with light brown laterally, and 

 more intensively dorsally, but always with a broad median white stripe. The gonads 

 and the adjacent pinnule segments are deep violet. The cirrus segments each have a 

 broad light brownish saddle. 



Remarks. — Dr. Gislen wrote that in a letter to him I had suggested that this 

 species might possibly be identical with, or nearly related to, the "Antedon impinnata" 

 mentioned by Dr. P. H. Carpenter from Mauritius. He said it is possible, though not 

 very likely, that this species might be nearly related to Carpenter's species — from 

 his very incomplete description one only learns that Pa, Pb, and Pj are absent — but 

 that it is identical with his species he considers to be out of the question, partly because 

 of the statements about the number of cirri and cirrus segments, and partly on account 

 of the geographical distribution. Besides, the statements about the pinnulation point 

 rather to a yoimg animal than to a fully grown individual. For in connection with 

 the notice of the absence of P2, Pa, and Pb nothing is said about Pi, and one must 

 therefore suppose that this pinnule is present. 



Localities. — Dr. Sixten Bock's Expedition to Japan, 1914; station 43; Bonin 

 Islands; northwest of Ototojima; 146 meters; July 31, 1914 [Gisl4n, 1922] (1, 

 U.S.N.M., E. 1110). 



Dr. Sixten Bock's Expedition to Japan, 1914; station 53; Bonin Islands; Higa- 

 shijima 2 miles east; 164 meters; sand and broken shells; August 7, 1914 [Gislen, 

 1922]. 



Willebrord Snellius station 60*; west of Zamboanga, Mindanao (lat. 6°58'00" 



