230 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 52 



Radials rather long being, in the median hne, about half as long 

 as broad ; first costals short, with concave distal ends and proximal 

 borders, over twice as broad as their lateral length, decreasing 

 slightly in diameter anteriorly, not in contact basally ; costal axillaries 

 rhombic, about as long as broad ; first brachials small, about three 

 times as long exteriorly as interiorly, not in contact interiorly, the 

 distal border concave ; second brachials much larger, irregularly 

 quadrate; third and fourth brachials (syzygial pair) half again as 

 long interiorly as exteriorly, about twice as broad as the exterior 

 length ; brachials as far as the second syzygy slightly wedge-shaped, 

 about twice as broad as long; first pinnule on the fifth ("fourth," 

 to use Carpenter's terminology) brachial, as in P. halanoides. 



Color. — Centro-dorsal purple ; arms purple, with a broad me-dian 

 line of white ; pinnules and cirri white. 



Type.— Ca.t. No. 25449, U. S. N. M., from Albatross Station No. 

 5178; north of Tablas Island; 78 fathoms. 



The greatly elongated centro-dorsal, which does not have promi- 

 nent interradial furrows, the elongation of the proximal and the 

 shortness of the distal cirrus joints, together with the length of the 

 radials and the absence of synarthrial tubercles, appear to diflfer- 

 entiate this species sharply from P. halanoides ; the absence of the 

 pinnule on the second brachial and the regular arrangement of the 

 cirri in ten columns, separate it at once from P. diomedece. 



EUMETRA, new genus 



Centro-dorsal hemispherical, the moderately large polar area 

 finely papillose ; cirrus sockets forty to sixty in number, in four or 

 five closely crowded alternating rows. 



Cirri long and slender, compressed, deciduous, about one-third the 

 length of the arms, with about twenty-five joints, all but the basal 

 two of which are greatly elongated, three times as long as broad or 

 longer ; opposing spine absent ; terminal claw not so long as the 

 penultimate joint, slender, sharp, and nearly straight. 



Costals and first two brachials in close lateral apposition, though 

 not laterally flattened, the synarthrial tubercles very prominent; 

 brachials essentially as in Antedon. 



First pinnule small and weak; second pinnule half as long again, 

 stouter and stififer; third pinnule over one-third longer than the sec- 

 ond, stouter, and very stiff; fourth resembling the seconrl, but stiflF 

 like the third ; following pinnules decreasing gradually in length and 

 stiffness ; distal pinnules about as long as the second, very slender, 

 the first two joints very short, the remainder greatly elongated, as 

 usual in the Antedonidae. 



