8 Clark — A Revision of Tlialassometridse and Himerometridse. 



7. Cenometra gen. nov. 



Genotype. — Himeromelra iDiicornlx A. H. Clark, 190S. 



Centro-ilorsal of moderate size, rather thick, ditscoidal, the dorsal pole 

 strongly concave ; cirrus sockets arranged in one or two closely crowded 

 alternating marginal rows. 



Cirri xv-xx, 30-45, stout, between one-fifth and one-sixth the length of 

 the arms ; cirrus joints snbequa-1, all alnjut twice as broad as long ; all 

 the joints with prominent distal ends, giving the cirri a strongly serrate 

 appearance dorsally ; joints of the outer half or two-thirds with paired 

 tubercles or small sj)int's. 



Radials just visil)le, sei)arated distally; i Brj entirely free laterally, 

 rounded dorsally, two or three times as broad as long ; i Brg little, if any, 

 longer than the first costals; ii Br always, iii Brand iv Br sometimes, 

 present, all 2, the last two developed oidy on the outer sides of each i Br 

 series; synarthrial tubercles not developed; division series and first brach- 

 ials bearing externally stout lateral processes as in Stephanometra, ytro- 

 gressively decreasing in size. 



Arms 20 to 30; first eight or nine lirachials approximately oblong, about 

 twice as broad as long, then becoming wedge-shaped, al tout twice as broad 

 as long, and distally less obliquely wedge-shaped. The l)rachials have 

 projecting and finely spinous distal ends. The second syzygy is at a con- 

 siderable distance from the calyx, varying from l)etween the fourteenth 

 and fifteenth to between the ninety-second and ninety-third, but usually 

 in the vicinity of the thirtieth brachial. 



P2 very large, stout and stifi", with twelve to twenty joints, most of 

 which are a little longer than Itroad, and have jn-ojecting and finely spin- 

 ous distal ends; Pj is slender and weak, tajtering, but with at least as 

 many joints as F2 ; P3 and tlie following pimuiles an^ slender and weak, 

 smaller than Pj ; distal pinnules nearly as long as P.^. 



Color (in spirits). — Light grayish l>lue, with very nunierous small ntund 

 red-brown spots, cirri yellow-brown ; or reddish-brown, the cirri yellow- 

 brown; P2 i« always light yellow-ln-own. 



Distrihution. — Ceylon, eastward to Amboina and the I'liilippinc Islands, 

 and northward to the (iulf of Tonkin. 



Deplli. — Littoral, and down certainly to I'i), and ]iossil)ly to :\{\ fathoms. 



The described species belonging to tins genus are : 



Cenometra ahbotti (A. II. Clark) 

 " bclla (Hartlaub) 



' ' brunnea ( I lartlaub ) 



" unicornis (A. II. Clark). 



S. Craspedometra gen. nov. 



Genotype. — Antedon ucidlcirra P. IL Cari)enter, iSS2. 



Centro-dorsal a large thick disk with a fiat or slightly convex dorsal 

 surface, the cirrus sockets usually in a single marginal row, rarely in two 

 irregular rows. 



