428 BULLETIN 82, UNITED STATES NATIONAL MUSEUM 



The specimen from Challenger station 174 was described by Carpenter as repre- 

 senting a new species, which he called Antedon tuberculata. According to Carpenter 

 the centrodorsal is saucer-shaped. The cirri are about XL, 20-25, rather stout 

 with tolerably uniform segments, few of which are longer than broad ; there is a small 

 opposing spine. The radials are concealed by the centrodorsal. The IBri are short 

 and rather convex dorsally and are not united laterally. The IBr 2 (auxiliaries) are 

 more than twice as long as the IBr! and are broadly pentagonal. The articulation 

 between the IBri and IBr 2 is rather tubercular. The division series are well sepa- 

 rated, and the postradial series may divide three times. The IIBr and IIIBr series 

 are 2 and bear synarthrial tubercles. IIIBr series are usually developed only on 

 the outer sides of the postradial series, so that each postradial series bears six arms 

 arranged in 2, 1, 1,2 order. The ventrolateral borders of all the ossicles of the division 

 series bear small tubercles, which project somewhat toward the ventral side. The 

 31 arms are about 90 mm. long and consist of 120 or more brachials, the first 8 or 10 

 of which are thick disks, those following being shortly triangular and later becoming 

 more discoidal again. The first syzygy is between brachials 3+4, the second from 

 between brachials 8 + 9 to between brachials 22+23, generally about brachials 

 13+14 or 15+16, and the distal intersyzygial interval is from 6 to 11, usually 8, 

 muscular articulations. 



The pinnules of the first pair (Pi and P a ) are about 9 mm. long and consist of 

 some 25 longish segments. The pinnules of the second pair (P 2 and P b ) are much 

 stouter and very stiff and tapering, reaching 15 mm. in length; they are composed of 

 about 12 segments all of which, except for those at the two ends, are much longer 

 than broad. The pinnules of the third pair (P 3 and P c ) are of the same character 

 but are rather shorter than the pinnules of the second pair. The pinnules of the 

 fourth pair (P 4 and P d ) are much smaller and less stiff. The disk is lost, but was 

 probably about 12 mm. in diameter. Sacculi are abundant along the ambulacral 

 grooves of both arms and pinnules. The color in alcohol is purplish white with 

 occasional dark purple bands, the ventral perisome greenish gray. 



I examined this specimen at the British Museum in 1910. There are 30 arms. 

 P! is slender and flexible, becoming very slender and flagellate distally. P 2 is much 

 enlarged, stiff and spinelike, nearly half again as long as P 3 , with 12 segments. P 3 

 resembles P 2 but is shorter and slightly less stout. P 4 is very short and small but is 

 more or less stiffened. P 6 resembles P 4 . 



Carpenter said that tuberculata, as well as spicata (from the Banda Sea; see beyond) 

 and indica (p. 439), is distinguished by the characters of the pinnules of the second 

 pair which are considerably longer than the pinnules of the first pair, though com- 

 posed of a smaller number of segments, which, however, are of very large size, some 

 of them reaching 1.5 mm. The segments decrease gradually in diameter from the 

 base to the tip of the pinnule so as to give the latter a remarkably stiff and tapering 

 appearance. He said that there is some indication of tliis in marginata (p. 447), but 

 its large pinnules are less stiff with relatively shorter segments, which are more uni- 

 form in diameter so that the pinnules lack the tapering and styliform appearance 

 which is so marked in spicata and tuberculata. In marginata also the cirri are both 

 smaller and have fewer segments than those of tuberculata, while the IBr : and IBr 2 

 (axillaries) are more nearly equal in length, and portions of the radials are visible. 



