Clark — A Ren'sion of TJudassomrtrhhe and Himcromctrulm. 9 



Cirri xv-xxv, .">5-()0, long and slender, stout hasallj^, distally tapering 

 gradually to a point; cirrus joints very short basally, becoming gradually 

 longer, and longest terminally; dorsal spines or carination absent; no 

 opposing «pine; terminal claw long (about as long as the penultimate 

 joint) and nearly straiglit. The cirri are over one-thii-d, and often nearly 

 one-half the arm length. 



Radials more f)r less completely concealed ; i Brj very short, united 

 laterally; i Br, short, free laterally; ii Br 4 (o + 4) ; iii Br 2, rarely 4 

 (3 + 4) ; IV Br 2; the division series are usually very irregular on ditt'er- 

 ent rays, i Br and division series rounded dorsally, well separated 

 laterally, with often a slight prominence of the synarthrial articulations. 



Arms 2i) to 35, long, moderately slender; first eight bracliials ajtproxi- 

 mately oblong (the first two wedge-shaped), two or three times as liroad 

 as long, then becoming oblicpiely wedge-shaped or triangular, but of the 

 same proportions, distally becoming less ol)liquely wedge-sha]ied, and 

 almost (though never quite) oblong in the distal half of the arm. 



Pi, stout basally, but becoming slender in the distal half, all the joints 

 short, the broad lower joints carinate ; Pj similar, Imt longer; Pj long 

 and rather stout, but gradually tapering distally, composed of very 

 numerous short joints, those in the basal half l)eing carinate; P3 similar, 

 but lunger and rather stouter, reaching to about half the cirrus length, 

 composed of numerous joints ; following pinnules decreasing in length and 

 stoutness, the distal pinnules being only aljout one-third as long as the 

 elongate proximal pinnules. The carination of the basal joints of the 

 lower pinnules is traceable to about the end of the pniximal third of the 

 arm. 



Culur (in spirits). — Nearly white, with traces of deep violet; fiesh- 

 colored, the perisome brown ; light brown ; deep purple, almost black ; or 

 purplish brown. 



Distribntion. — Sydney, New South "Wales, northward to Amboina, 

 Singapore and Hong Kong. 



Drv-//;.— Littoral. 



Lack of material has prevented my confirming or dispniving Hartlaub's 

 disjMisitidU of the descrilied species of this genus; I therefdre list all of the 

 nominal species referable to this genus which have been described: 



Cros])rd()metra ar^aicirra (P. H. Carpenter) 

 " aiistralis (P. H. Carpenter) 



" hipartqnnna (P. H. Carpenter) 



" ludovici (P. H. Carpenter). 



9. Stephanometra gen. nov. 



Genotype. — Antedon monacantha Ilartlaub, ISiK). 



Centro-dorsal moderate to small, discoidal witli sloping sides, or sub- 

 hemispherical, the dorsal polar area small, usually flat or slightly convex, 

 more rarely slightly concave; cirrus sockets arranged in one and a partial 

 second to two and a partial third closely crowded alternating rows. 



