538 BULLETIN 82, UNITED STATES NATIONAL MUSEUM 



The radials are scarcely visible. The rays divide four times. The IIBr, IIIBr, 

 IVBr, and VBr series are all 4 (3 + 4). The first ossicles following an axillary are 

 interiorly united. 



The pinnules of the division series are more than 40 mm. long and are as large at 

 the base as, and broader than, the cirri. Most of the pinnules have the tips broken off, 

 but some are entire, and these have about 60 segments. The terminal comb is feebly 

 developed. Koehler said that the pinnules showed the characters indicated by Car- 

 penter ; that is, that the ventral edges of the segments are produced so as to stand up 

 as plates sloping slightly inward toward the ambulacral groove. 



The disk is 40 mm. in diameter. The mouth is interradial. 



The color as preserved is greenish olive. 



One of the specimens collected by the Danish expedition to the Kei Islands at 

 Amboina has 78 arms 170 mm. long; the cirri have 24-27 segments. The other 

 specimen is small, with 60 arms 150 mm. long; the longest cirri have 21-27 segments. 



The specimen from the south coast of Ceram was described by Carpenter as a 

 distinct species under the name of Actinometra peronii. 



The centrodorsal, according to Carpenter, is a convex disk somewhat hollowed in 

 the center. The cirri are arranged in 2 rows. 



The cirri are XXV-XXX, about 30, stout and long, sometimes reaching 40 mm. 

 in length. The segments are tolerably equal hi leguth. They increase in length up 

 to about the sixth and then slowly diminish. The later segments are somewhat 

 compressed laterally and the penultimate bears a faint opposing spine. 



The radials are only visible in the interradial angles, where the small tubercles 

 representing the ends of the basal rays are visible. The IBr[ are planoconvex, barely 

 meeting laterally. The IBr 2 (axillaries) are widely pentagonal, with rather sharp 

 distal angles. The rays divide three, or occasionally four, times. All of the division 

 series are 4 (3 + 4). The IIBr! are very slightly united interiorly, the first ossicles 

 after the other axillaries being rather more closely united. The rays are well separated, 

 the perisome between them and that between their first divisions being covered with 

 minute plates. 



The 66 arms are about 125 mm. long. They are composed of 150-200 brachials. 

 The first 2 brachials are somewhat variable in shape, the first being rather the longer. 

 The first syzygial pair (composed of brachials 3 + 4) is oblong or nearly square. The 

 next 5 or 6 brachials are nearly oblong, those following gradually becoming short 

 and sharply wedge-shaped, with slightly raised distal edges. Toward the middle of 

 the arms the brachials are shorter and blunter, with finely denticulate edges, and the 

 terminal ones are oblong or nearly square. The distal margins of most of the brachials 

 have pointed anterior projections which occur alternately on opposite sides. The 

 anterior arms are slightly longer than the posterior. 



Syzygies occur between brachials 3 + 4, and again from between brachials 20 + 21 

 to between brachials 26 + 27, and distally at intervals of from 4 to 10, usually 4 or 5, 

 muscular articulations. 



The second elements of all the division series bear long pinnules. The first 2 are 

 tolerably equal, 30 mm. long, with large basal segments. The size decreases rapidly 

 to about the eighth brachial, after which the pinnules are uniform in length for a few 



