130 BULLETIN 82, UNITED STATES NATIONAL MUSEUM 



The 10 arms are all broken off at the first syzygy. The first brachials are short, 

 deeply incised by the second; their exterior length is much greater than the interior 

 and more than twice the median, the distal border being strongly concave. The second 

 brachials are irregularly quadrate with a strong posterior process incising the first; the 

 proximal three-fourths of the median line is elevated as in the IBr 2 . The third brachial 

 (hypozygal of the first syzygial pair) is oblong, very short, about five times as broad 

 as long. 



P! is 5.5 mm. long with 19 segments of which the first eight are much larger, 

 though proportionately shorter, than those succeeding; the second-seventh have thin, 

 very high, carinate processes that reach a maximum on the fourth, thence rapidly 

 decreasing in height distally. After the eighth segment the pinnule is relatively slender 

 and tapers gradually to the tip. In lateral view the pinnule appears enormously swollen 

 in the proximal three-fifths (first eight segments), the swelling reaching a maximum on 

 the fourth segment and decreasing rapidly distally; beyond the eighth segment the 

 pinnule is slender and evenly tapering, composed of segments most of which are about 

 as long as broad, with numerous spinules along the prismatic ridge. 



Locality. — Siboga station 211; southeast of Sindjai, Celebes (lat. 5°40'42" S., long. 

 120°45'30" E.); 1,158 meters; coarse gray mud, the superficial layer more fluid and 

 brown; September 25, 1899 [A. H. Clark, 1912, 1918] (1, Amsterdam Mus.). 



History. — This species is known only from the single specimen originally described 

 in 1912 and redescribed and figured in 1918. 



STIREMETRA CARINIFERA A. H. Clark 



[See vol. 1, pt. 1, fig. 97, p. 159.] 



Stiremetra carinifera A. H. Clark, Crinoids of the Indian Ocean, 1912, p. 211 (description; Inves- 

 tigator station 232); Unstalked crinoids of the <St'6offa-Exped., 1918, p. 161 (in key; range; 

 references). 



Diagnostic features. — The IBri have the proximal and distal edges prominently 

 everted, smooth, somewhat wavy, or coarsely tubercular, and a prominent median 

 rounded carination; the brachials do not bear overlapping spines; and the cirri are 

 arranged in 10 definite columns on the centrodorsal. There are 10 arms, and the 

 cirri are 45-50 mm. long with 50-64 segments. 



Description.— The centrodorsal is large and columnar with the sides practically 

 parallel, 5 mm. in diameter at the base and 3.5 mm. high interradially. The cirrus 

 sockets are arranged in 10 columns, 3 or 4 sockets to a column, the columns segregated 

 into five interradial pairs. The two columns of each pair are separated by a narrow 

 ridge of moderate height; in the midradial line the pairs of columns are separated by 

 deep V-shaped furrows as broad as the adjacent cirrus sockets; the central groovo of 

 these furrows is slightly rounded. The dorsal pole of the centrodorsal is flattened, 

 with the surface more or less irregular 



The cirri are XXXV, 50-64 (usually 57 or 58), from 45 to 50 mm. long. The 

 first segment is very short, those following gradually increasing in length and becom- 

 ing about as long as broad on the fifth and nearly or quite twice as long as broad on 

 the eighth (more rarely seventh), which is a transition segment. The following seg- 

 ments gradually decrease in length, becoming about as long as broad on the twelfth 

 or thirteenth, and after the twenty-fifth about twice as broad as long. On the second 



