A MONOGRAPH OF THE EXISTING CRINOIDS 265 



Dr. Clark said that one very small comatulid, apparently a Heterometra, and 

 hence almost surely this species, was taken in 1932 at Broome. There are 13 arms 

 about 15 mm. long. The division series are 4(3+4), but the cirri are only X, 13. 

 The color is very pale brown, the cirri with a very slight tinge of violet. 



The single specimen from Mjoberg's station 7 and the two from his station 11 

 were thus described by Dr. Torsten Gislen: The centrodorsal is thickly discoidal with 

 an almost flat papillated dorsal surface which is from 3 to 4 mm. in width. The 

 cirrus sockets are arranged in two rows. In two of the specimens the cirri are XXIX, 

 33-46, the marginal cirri being 38-46 and those of the distal row having 33-39 seg- 

 ments. The length of the cirri is 25 to 30 mm. Included in the number of the cirri 

 are some empty fresh sockets from several of which young cirri are regenerating. In 

 the marginal cirri dorsal carination begins at the nineteenth-twenty-first segment 

 (in an exceptional case at the twelfth) while in the cirri of the distal row it begins 

 at the fourteenth-sixteenth. The third specimen has the cirri XXXV, 35-40; the 

 dorsal carination first appears on the very last segments. The proximal cirrus seg- 

 ments are laterally flattened, and the distal are laterally compressed. The longest 

 proximal segments are one-third again as broad as long, and the distal segments are 

 twice as broad as long. The first segment is short, four times as broad as long. The 

 opposing spine is usually a little stronger than the spines on the preceding segments. 

 The terminal claw is curved, and is at least as long as the penultimate segment. 



The anterolateral angles of the radials project as small triangular portions 

 between the bases of the cirri and the IBrj. Their surface is strongly granulated — 

 they are almost completely concealed by the centrodorsal, however, in the specimen 

 from station 7. The IBrj are laterally in contact. The IBri and IBr 2 are united by 

 synarthry, each having a median tubercle. This points directly up on the IBri but 

 is bent backward on the IBr 2 so that the two tubercles converge to a joint tip. This 

 is repeated on all the pairs of ossicles united by synarthry. The IIBr series are 

 4(3 + 4), in exceptional cases four arranged in two synarthrial pairs; in the latter case 

 each pair of ossicles shows a synarthrial tubercle. In the specimen from station 7 

 two of the IIBr series are 2. The IIIBr series are 2, in a few cases 2(1+2). The 

 ossicles following the axillaries are united interiorly. The syzygies in the division 

 series unite a very short discoidal hypozygal and an irregularly triangular epizygal — 

 the axillary. The division series and arm bases are in close lateral apposition, but 

 they are little flattened laterally. The elements of the division series and the 

 proximal brachials are plump and swollen. 



The three specimens have 23, 24, and 30 arms, 85 to 100 mm. in length. The first 

 10 brachials are discoidal and those following become wedge-shaped, and again dis- 

 coidal in the distal portion of the arms. From the seventh or eighth brachials onward 

 there are thick transverse dorsal prominences (articular tubercles), which are devel- 

 oped most strongly on the side of the segment that carries the pinnule, thus 

 alternating on the right and left sides. The distal segments are collar-shaped. 



Gislen gave the distribution of the syzygies in a typical postradial series. The 

 IBr series is 2. The two IIBr series are 4(3+4). There are two IIIBr series, both 

 internally developed, one 2 and the other 2(1 + 2). On one of the outermost arms, 

 arising from a IIBr axillary, the syzygies are between brachials 3 + 4, 12 + 13, and 



208244—40 18 



