248 PROCEEDINGS OF THE NATIONAL MUSEUM VOL.83 



EOMETRA, new genus 



Diagnosis. — A genus of Zenometrmae in which the centrodorsal is 

 small, conical with somewhat swollen sides, about as high as broad at 

 the base, almost completely covered with cirrus sockets, which are 

 arranged in 10 closely crowded columns of 2 or 3 each; the cirri are 

 slender and only slightly curved distally, gradually tapering to a fine 

 point, with all the segments except the basal much elongated and 

 without dorsal processes; the elements of the IBr series and lower 

 brachials are smooth and not in lateral contact; all the pinnules are 

 present; Pi and Pa are similar, the latter the longer; P3 and the pinnules 

 following are much longer than Po. 



Genotype. — Psathyrometra antardica A. H. Clark, 1915. 



Range. — Antarctic; 2,725 meters. 



Included species. — Eometra antardica (A. H. Clark). 



BOLEOMETRA, new genus 



Diagnosis. — A genus of Bathymetrinae in which the first six or 

 seven segments of Pi are as broad as, or broader than, long; there 

 are not more than 30 cirrus segments; and the brachials and pinnule 

 segments have smooth distal edges. 



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



Range. — Southwestern Japan; 195 meters. 



Included species. — Boleometra clio (A. H. Clark). 



RETIOMETRA, new genus 



Diagnosis. — A genus of Bathymetrinae in which Pi is much elon- 

 gated, about twice as long as P2, and composed of 20 to 30 segments; 

 P2 resembles the succeeding pinnules and bears a large gonad; the 

 brachials have shghtly produced and spinous distal ends; the centro- 

 dorsal is low hemispherical; and the cirri are short with 11 to 20 

 segments of which the longest are not more than three times as long 

 as broad and the distal do not bear dorsal spines. 



Genotype. — Retiometra alascana, new species. 



Range. — Southeastern portion of Bering Sea and the Gulf of 

 Alaska; vicinity of Marion Island (southeast of the Cape of Good 

 Hope); 91-1,270 meters. 



Included species. — Retiometra alascana, new species; Retiometra 

 exigua (P. H. Carpenter). 



RETIOMETRA ALASCANA, new species 



Description. — The centrodorsal is very low with a broad bare dorsal 

 pole about one-third the diameter of the centrodorsal in width; the 

 45 to 60 cirrus sockets are closely crowded and increase slowly in size 

 from the vicinity of the bare dorsal pole to the periphery. 



