Clark — New Genera of Unstalked Crinolds. 127 



hemispherical, the cirrus sockets irregular in distribution, but approach- 

 ing fifteen columns of two each. Cirri with about thirty joints, a few of 

 the proximal longer than broad, the remainder squarish, the distal not- 

 bearing dorsal spines; the opposing spine is prominent, terminally situ- 

 ated, reaching in length rather more than half the diameter of the pen- 

 ultimate joint; the spine is almost an isosceles triangle, arising from the 

 entire dorsal surface of the joint ; terminal claw rather stout, well curved, 

 rather longer than the penultimate joint. Interradial areas with two or 

 three columns of small, rounded interradial plates, not in contact; inter- 

 brachial plates may or may not be present between the two arms of each 

 pair ; disk naked. Costals rather narrow, well separated, the first oblong, 

 about twice as broad as long, the second pentagonal, both occasionally 

 furnished with small dentate processes. Ten arms of comparatively 

 elongate joints. First pinnule longer and stiffer than those following, 

 but shorter than the distal ; the pinnule of the fourth (epizygal) brachial 

 is absent. 



Color. — Salmon red, the pinnules the same, or yellow; cirri white. 



Geographic distribution. — Only known from southern Japan, from the 

 Korean Straits to Sagami Bay. 



Depth.— 50 to 100 fathoms. 



The presence of interradial and interbrachial plates on an otherwise 

 naked disk, distinguish this genus at once from all other genera of Ante- 

 donidse; the absence of the first inner pinnule shoidd be noticed. The 

 only species at present known is, 



Erythrometra ruber (A. H. Clark). 



Thaumatometra gen. now 



Genotype. — Antedon ciliata A. II. Clark, 1907 (— Antedon tenuis A. H. 

 Clark, 1907). 



Radial facets about as broad as high, the muscular fossa? large and well 

 rounded, distally separated by a narrow, sharp notch, which extends for 

 less than one-quarter of the length of their apposed sides; interarticular 

 foss;e remarkably small, the ridge separating them from the muscular 

 fossa? horizontal in its outer half, gently oblique in its inner. Centro- 

 dorsal conical or sub-conical, the sides convex, somewhat thickly, and 

 almost entirely, covered with crowded cirrus sockets. Cirri slender, 

 numerous, with fifteen to thirty subequal joints, all of which are usually 

 longer than broad; there may be a slight ventral overlap, but spines are 

 not developed ; the opposing spine is prominent, terminally situated, and 

 directly obliquely forward. Radials almost, or entirely, hidden by the 

 centro-dorsal ; costals moderately short, the costal axillary pentagonal, 

 more or less produced posteriorly. Ten arms, the lowest brachials oblong, 

 broader than long, then triangular about as long as, or rather longer 

 than, broad, distally becoming much elongate, quadrate, or almost oblong, 

 with swollen articulations. The calyx and brachials are often more or 

 less spinous. The first pinnule is slender, composed of elongated joints, 

 and may be somewhat, or not at all, longer than the second ; the second 



