122 BULLETIN 82, UNITED STATES NATIONAL MUSEUM 



segments of which the first is about three times as broad as long, and those following 

 gradually increase in length becoming as long as broad on the ninth and slightly longer 

 than broad terminally. The longer proximal segments are rather strongly carinate, 

 the carination having a straight profile which is parallel with the long axis of the 

 segments. The short outer segments have slightly prominent distal ends. P 2 is 

 similar, but very slightly smaller and shorter. P 3 is 2.5 mm. long, composed of 12 

 segments; except for its smaller size it is similar to the preceding pinnules. P 4 is 2 

 mm. long, with 12 segments, of which the first three are much broader than long, the 

 fourth is about as long as broad, and the distal are twice as long as broad. P e is 2.5 

 mm. long, with 12 segments, and resembles P 4 , but it is very slightly stouter basally 

 and the distal segments are longer. The following pinnules resemble P 6 . The 

 distal pinnules are 4 mm. long, with 15 segments, of which the distal are nearly or 

 quite three times as long as broad. 



The color in alcohol is white with numerous regular purple spots on the division 

 series and arm bases and in bandlike areas on the distal portions of the arms. The 

 cirri are white with a band of purple on each segment. 



Notes. A specimen from Siboga station 273, which is similar to the type, has 17 

 arms, with 5 IIBr 4 (3+4) series and 2 IIBr 2 series; the cirri are XVII, 18, 9 mm. 

 long. The remaining two specimens from this station are small. 



Reichensperger referred to this species a 10-armed young individual from the Aru 

 Islands. The 10 graceful, slender arms are 27 mm. long. The centrodorsal is thin, 

 with the cirri arranged in a single irregular row. The cirri are XV, 13-15, up to 5 mm. 

 in length. The first segment is short and laterally compressed, the second is notice- 

 ably longer than broad, and the third, fourth, and fifth are the longest, about twice 

 as long as broad. The length of the segments then decreases slowly so that the last is 

 broader than long. The opposing spine is very long and straight. The terminal claw 

 is about twice as long as the penultimate segment, long and strongly curved. From 

 the fourth or fifth segment onward strong dorsal spines are developed. PI is 4 mm. 

 long, with 20-22 segments, of which the first is broader than long, the next 10 or so are 

 about as long as broad, and the remainder slightly elongated, the pinnule becoming 

 flagellate terminally. P 2 is 3.5 mm. long, with about 18 segments, and resembles PI. 

 P 3 is scarcely 2 mm. long and is composed of 11 or 12 segments. P 4 is the shortest, 

 about 1.5 mm. long, moderately stout, with 8 or 9 segments. The following pinnules 

 increase in length and in the number of their component segments. P 6 has 12 seg- 

 ments. The distal pinnules are about 3 mm. long. The IBr series are rather short, 

 and laterally free. The brachials are relatively long, with the ends only slightly 

 oblique. The lowest brachials bear slight ventrolateral processes. The disk is lacking. 

 The color in life was light red. 



Of the three specimens from Port Curtis one has 12 and two have 11 arms, 25 

 mm. to 33 mm. long. The cirri of the largest specimen are XV, 14-18 (usually 15). 



Localities. Siboga station 273; anchorage off Pulu Jedan, eastern coast of the Aru 

 Islands (pearl banks); 13 meters; sand and shells; December 23-26, 1899 [A. H. Clark, 

 1912, 1913, 1918] (4, U. S. N. M., E. 442; Amsterdam Mus.). 



Aru Islands; Dr. H. Merton's station 4; Dobo Strait; 50 meters; calcareous rock; 

 March 20, 1908 [Reichensperger, 1913]. 



