A MONOGRAPH OF THE EXISTING CRINOIDS 597 



Another specimen (542) has 24 arms. Of the IIBr series, 7 are 2, 2 are 4 (3 + 4), 

 and 1 is missing. The bare dorsal pole of the centrodorsal is slightly concave, 2.5 mm. 

 in diameter. The cirri are XI, 14. 



One of the examples from the southwest reef at Mer (538) has 23 arms about 

 60 mm. long. The cirri are XIII, 14-16. The other (539) has 29 arms about 65 mm. 

 long. One of the IIBr series is 2, all the other division series being 4 (3 + 4). The 

 cirri are XI, 14-15. 



Five other specimens from this locality (537) have 20, 21, 22, 25, and 29 arms. 



The specimen taken on the southwest reef on September 29, 1913, has 24 arms 

 about 65 mm. long. Of the IIBr series, 6 are 4 (3 + 4) and 4 are 2. The cirri are 

 XX, 15-16, with several not fully formed. 



This is the type of Comanthus luteqfuscum H. L. Clark which was thus described. 



The centrodorsal is small, thick, with the bare dorsal surface flat or a trifle 

 concave, 2 mm. in diameter. 



The cirri are XVIII-XXII, 13-17, rather short, about 10 mm. long. Except 

 for the fourth-seventh the cirrus segments are short, and broader than long. Except 

 for 7 or 8 basal segments, each segment has a dorsal elevation of more or less promi- 

 nence. This may be a tubercle, a spine, or a rough transverse ridge: it is often 

 conspicuous. 



The radials are in close lateral apposition. The IBr t are notably broader than 

 the IBr 2 (axillaries) and in broad lateral contact. The axillaries are almost triangu- 

 lar, very short and broad, and well separated laterally. The IIBr series are usually 

 4 (3 + 4), but occasionally 2. The IIBr i are in close contact interiorly. The IIIBr 

 series are usually 4 (3+4), but sometimes 2. The IIIBr i are in contact interiorly. 



The 20-30 arms are notably short, from 50 to 60 mm. in length, usually approxi- 

 mately equal, "but sometimes distinctly longer on one side of the animal than on 

 the other." Each arm is made up of from 80 to 100 brachials, which, except at the 

 arm tip, are low, more or less discoidal, and have everted and finely serrate distal 

 margins, particularly near the middle of the arm. The first brachials are in contact 

 interiorly. 



Syzygies occur between brachials 3 + 4, 10 + 1 1 , or 1 1 + 12, and distally at intervals 

 of from 4 to 6 muscular articulations. 



The oral pinnules have 30 or more segments, of which 8 or more make up the 

 comb. The arm pinnules have only a dozen segments. Even the distal pinnules 

 are short. The pinnules at the base of the arm and near the middle are stout, and 

 their component segments have everted and finely serrate distal ends. 



The specimen from the Great Barrier Reef has 26 arms. Of the IIBr series, 5 

 are 4 (3+4) and 5 are 2. The cirri are XV, 15-17, with the distal portion strongly 

 recurved. 



The specimen from Ugi has 20 arms 60 mm. long. Of the 9 IIBr series, 6 are 

 4 (3 + 4) and 3 are 2. On one postradial series, which bears 2 IIBr series, there is a 

 IIIBr series, developed externally. 



Of the 2 specimens from New Caledonia 1 has 24 and the other 26 arms. 



The specimen from Suau Point, Fiji, has the cirri XXII, 14. 



The specimen labeled Tonga and Fiji in the Hamburg Museum has 39 arms. 



