A MONOGRAPH OF THE EXISTING CRINOIDS 93 



from the Cape St. James-Hong Kong cable (R. H. Ellis), June 4, 1927 [A. H. Clark, 

 1929](1,B.M.). 



History. This species is only known from the single specimen collected by the 

 Patrol off Cape Padaran in 80 fathoms. Through the courtesy of C. C. A. Monro, of 

 the British Museum, this specimen was sent to me for study in 1928 and was described 

 and figured by me in 1929. 



ICONOMETRA BELLONA (A. H. Clark) 



Oligomctrides bellona A. H. CLARK, Proc. Biol. Soc. Washington, vol. 33, 1920, pp. 21, 22 (description; 



southwest of Sorsog6n Bay, Luz6n, 9-40 fms.; Port Galora, Mindoro). 

 Iconometra bellona A. H. CLARK, Journ. Linn. Soc. (Zool.), vol. 36, No. 249, 1929, p. 643 (listed). 



Diagnostic features. The 11 arms are about 100 mm. long; the cirri are XXIV, 

 21-23, about 13 mm. long, with the dorsal transverse ridges on the segments proximal; 

 P 2 and P 3 are similar and of about the same length, 16 mm. long with 14-16 segments, 

 'longer than PI . 



Description. The centrodorsal is thin discoidal, the dorsal pole flat or slightly 

 convex, about 2.5 mm. in diameter, and studded with well-spaced and evenly dis- 

 tributed granular tubercles. Within the circle of cirri dorsally there is a more or 

 less complete circle of empty cirrus sockets, each occupied in the center by a more or 

 less hemispherical median tubercle. 



The cirri are XXIV, 21-23, about 13 mm. long. The cirrus segments are sub- 

 equal, not quite so long as broad. On the third the proximal border is broadly 

 thickened, this thickening on the fourth and folio whig becoming a high transverse ridge 

 with a sharp straight crest which on the segments in the outer half of the cirri becomes, 

 when the segments are viewed endwise, evenly convex, then gradually gablelike, and 

 on the antepenultimate reduced to a single spine situated on the proximal edge of the 

 segment. On some of the middle and outer segments of certain cirri midway between 

 the proximal transverse ridge and the distal edge there is a transverse row of minute 

 tubercles representing the distal transverse ridge in 0. adeonae; these, however, are 

 not always present, and when present are inconspicuous. 



The division series are broad and thin and in lateral contact, with their borders 

 narrowly flattened against those of the plates on cither side and therefore straight. 

 The synarthrial tubercles are very prominent and sharp, and are slightly produced. 

 The IIBr series are 2. 



The arms are 11 in number, about 100 mm. long, resembling those of 0. adeonae. 



The pinnules are essentially similar to those of 0. adeonae. PI is 13 mm. long, 

 rather stout, stiff, tapering evenly from the base to the tip, and is composed of 15 

 segments all but the first of which are longer than broad, the outer being about twice 

 as long as broad. P 2 is similar to P,, 16 mm. long, but proportionately stouter and 

 tapering more gradually, with 15 or 16 segments of which the first is broader than long, 

 the second is about as long as broad, and the following are longer than broad, mostly 

 about twice as long as broad. P 3 is similar to P 2 and of the same length or very 

 slightly shorter, with 14 or 15 segments. P 4 is similar to P 3 , 12 mm. long with 14 

 segments. The following pinnules are shorter and more flexible, with shorter seg- 

 ments. P 5 is 9 mm. long with 12 segments. The distal pinnules are slender, 13 mm. 

 long with 22 segments. 



