NO. 1798. CRINOIDS COLLECTED BY THE ALBATROSS— CLARK. 539 



Genus CATOPTOMETRA. 

 CATOPTOMETRA OPHIURA, new species. 



Centrodorsal thin-discoidal with a broad moderately concave 

 polar area 5 mm. to 8 mm. in diameter marked in the center by a 

 shallow rounded pit; cirrus sockets in two closely crowded irregular 

 marginal rows. 



Cirri XXVII, 15-18 (usually 17), 22 mm. long; first segment 

 about twice as broad as long, second not quite so long as broad, third 

 half again as long as the median diameter, fourth and fifth twice as 

 long as the median diameter, the following gradually becoming very 

 slightly shorter so that the terminal segments are half again as long 

 as broad; dorsal and ventral edge of the longer proximal segments, 

 especially the former, rather strongly concave, this feature gradually 

 dying away distally; lateral edges of these longer proximal segments 

 very strongly concave, this character gradually becoming less marked 

 but persisting to the end of the cirrus; penultimate segment about 

 one-third longer than broad; opposing spine terminal, small and 

 inconspicuous; terminal claw half again as long as the penultimate 

 segment, slender and slightly curved. 



Radials barely visible in the angles of the calyx; IBrj very short 

 and bandlike, oblong; IBrj triangular, nearly three times as broad 

 as long; IBrj and , well separated laterally; IIBr 4 (3 + 4); IIBr^ 

 interiorly united for the proximal half or two-thirds, diverging so as 

 to make right angles with each other distally; IIIBr (when present) 

 2 always developed interiorly in 1, 2, 2, 1 order; synarthrial tubercles 

 sharp and prominent. 



Twenty to twenty-seven arms 180 mm. long; first brachial wedge- 

 shaped, about twice as broad as long exteriorly, interiorly united for 

 about the proximal two-thirds; second brachial about the same size 

 but more obliquely wedge-shaped; third and fourth brachials 

 (syzygial pair) slightly longer interiorly than exteriorly, about twice 

 as broad as the median length; following five brachials oblong or 

 slightly wedge-shaped, two to three times as broad as long, then 

 becoming triangular, nearly as long as broad, then triangular and as 

 long as broad, and distally obliquely wedge-shaped, becoming ter- 

 minally longer than broad; distal edges of the tenth and following 

 brachials moderately overlapping and finely spinous. Syzygies occur 

 between the third and fourth brachials, again between the nineteenth 

 and twentieth to thirty-sixth and thirty-seventh (usually about the 

 twenty-seventh and twenty-eighth) and distally at intervals of eight 

 to sixteen (usually ten or eleven) oblique muscular articulations. 



Pj, small and slender, 6 mm. long, with twenty-five to thirty seg- 

 ments, most of which are about as long as broad; the second to the 

 fifth bear strong dorsal projections; Pj 7 mm. to 8 mm. long, slender, 

 the second to the fourth segments with dorsal projections which are 



