278 BULLETIN 82, UNITED STATES NATIONAL MUSEUM 



length, about twice as long as broad at the ends. The cirri have 24-36 (usually 

 30-33) segments. The 10-13 arms are 90-120 mm. long. 



Description. The cirri are VIII-XIII, 24-36 (usually 30-33), 26 to 32 mm. 

 (usually about 30 mm.) long, very slender, tapering gradually to the end of the 

 proximal third and being especially slender from that point onward, recalling the 

 cirri of Leptometra celtica. All the cirrus segments are approximately subequal in 

 length, about twice as long as broad at the ends, though those in the distal third of 

 the cirri are slightly carinate, which makes them appear slightly shorter, and those in 

 the proximal half are slightly longer with slightly expanded ends. On the outermost 

 segments there is a slight indication of dorsal tubercles. 



The 10 to 13 (usually 11-13) arms are 90-120 mm. long. 



P! is 7.5 mm. long, with 18 segments, which, gradually increasing in length, 

 become about as long as broad on the fourth or fifth and twice as long as broad ter- 

 minally; the second-eighth have a strong, though rounded, supplementary ridge. 

 P 2 is 10.5 mm. long, with 17 segments, slightly stouter basally than P t , tapering less 

 gradually and composed of longer segments; there is a supplementary ridge on the 

 second-ninth segments. P 3 is similar to P 2 , 9 mm. long. P 4 is 6 mm. long, with 11 

 segments and has a supplementary ridge on the second-fourth or -fifth. P 2 and P 3 

 are not stouter basally than the succeeding pinnules, but they taper with slightly less 

 rapidity; the distal angles of their component segments are only slightly swollen and 

 produced. The distal pinnules are 10 mm. long and are composed of 20 segments. 



The color in alcohol is brownish white with occasional narrow bands of rusty 

 on the arms ; the cirri are white. 



Notes. The characters of the six specimens from Siboga station 318 are included 

 in the preceding description. 



One of the specimens from Siboga station 320 has 11 arms 120 mm. long with a 

 single IIBr 4(3+4) series; the cirri are 30 mm. long and are composed of 33 segments. 

 The other is smaller with 12 arms about 55 mm. long, both the IIBr series being 2, 

 and the cirri 20 mm. long. 



Remarks. This species is most closely related to H. producta, but it is even more 

 slender and delicate. The elongate distal cirrus segments serve to distinguish it at 

 once. 



Localities. Siboga station 318; south of eastern Borneo (lat. 636'30" S., long. 

 11455'30" E.); 88 meters; fine yellowish gray mud; February 22, 1900 [A. H. Clark, 

 1912, 1918] (6, U.S.N.M., E. 431 ; Amsterdam Mus.). 



Siboga station 320; south of eastern Borneo Gat. 605'00" S., long. 11407'00" 

 E.); 82 meters; fine yellowish gray mud; February 22, 1900 [A. H. Clark, 1918] (2, 

 U.S.N.M., E. 420 ; Amsterdam Mus.). 



History. This species was first described in 1912 from specimens from Siboga 

 station 318. In 1918 it was redescribed and figured, and specimens were recorded 

 also from Siboga station 320. 



HETEBOMETBA VARDPINNA (P. H. Carpenter) 

 PLATE 26, FIGURES 104, 105 



Antedon variipinna P. H. CARPENTER, Journ. Linu. Soc. (Zool.), vol. 16, 1882, p. 506 (description; 

 Canton, China); Proc. Zool. Soc. London, 1882 (1883), p. 746 (specific formula); Challenger 



