Clark — A Revision of Tlialassometridse and Himerometridse. 15 



Pi longer than Pj, though not especially enlarged; following pinnules 

 shorter, with the hasal joints less carinate; distal pinnules as long as, or 

 rather longer than, P,. 



Color. — Bright yellow, sometimes more or less banded or blotched with 

 white ; cirri lighter in color than the arms. 



Distribution. — Ki Islands northward to Japan. 

 Depth. — 80 to 142, possibly to 152 fathoms. 

 The species referable to this genus are : 



Stenometra conifera (Hartlaub) 



" diadema (A. H. Clark) 



hana (A. H. Clark) 

 " quinquecostata (P. H. Carpenter). 



15. Stiremetra gen. nov. 



Genotype. — Antedon acutiradia P. H. Carpenter, 1888. 



Centro-dorsal hemispherical or bluntly conical, the dorsal pole more or 

 less papillose; cirrus sockets in one or two rows, and in two columns in 

 each radial area, though the columns are not especially marked off. 



Cirri xv-xxv, 40-50, cirrus joints proximally longer than broad, but 

 becoming very short in the distal half, the joints in the distal two-thirds 

 at least, sometimes all of the joints, bearing prominent dorsal spines. 



Radials concealed; i Br, very short, band-like, deeply incised in the 

 median line; i Br^ large, rhomljic or shield-shaped, with a strong posterior 

 projection incising the i Brj, and a strong median keel. 



Arms 10; first two brachials sharply carinate, but following brachials 

 rounded dorsally; in the distal two-thirds of the arm the brachials 

 developing prominent median overlapping spines, though not appearing 

 to be much compressed laterally. The i Br and lower brachials are in 

 close aiiposition and are sharply flattened laterally. 



Pi much larger than Pj, with large lower joints which are rather 

 strongly carinate. 



Color (in spirits). — " Light brownish-white." 



Distribution. — Kermadec Islands and Port Jackson, to Fiji. 



Depth.— &dO to 1350 fathoms. 



The included species are : 



Stiremetra acutiradia (P. H. Carpenter) 

 " breviradia (P. H. Carjienter) 



" spinicirra (P. H. Carpenter). 



16. Parametra gen. nov. 



Genotype. — Antedon orion A. H. Clark, 1907. 



Centro-dorsal hemispherical or thick-discoidal, moderate or rather 

 small, the marginal cirri arranged in one or two rows, and approximately 

 in two or three colunnis in each radial area. 



Cirri ix-xxv, 15-27, up to tbe fifth to the seventh joint rounded, stout, 

 smooth, and with a dull surface, then becoming laterally compressed, pol- 

 ished, and bearing low dorsal spines; cirri only one-sixth or one-.seventh 

 of the arm length. 



