476 



BULLETIN 82, UNITED STATES NATIONAL MUSEUM 



VOLUME 1 



b 



mm 



FIGURE 22. Erythrometra rubra (A. H. 

 Clark), U.S.N.M., 35642, Albatross station 

 3755: a, Postradial series; b, PI. 



p. 235 (in key; range), p. 236 (references). GisLfiN, Nova Acta Reg. Soc. Sci. Upsaliensis, ser. 4, 

 vol. 5, No. 6, 1922, pp. 141, 142; figs. 150-152, p. 146. 



Erythrometra rubra GiSLiiN, Nova Acta Reg. Soc. Sci. Upsaliensis, ser. 4, vol. 5, No. 6, 1922, p. 140 

 (Bock sta. 11; Sp. 2, but not Sp. 1 and 3, which are young Perometra diomedeae); Vid. Medd. 

 Nat. Foren. K0benhavn, vol. 83, 1927, p. 3 (sta. 9; 162 meters), footnote 1 (of Gislen, 1922, in 

 part= Perometra diomedeae), p. 48 (sta. 9; notes), p. 68 (listed); fig. 60, p. 44. 



Diagnostic features. The arms are not known to exceed 35 mm. in length, and 

 the cirri have up to 30 segments. 



Description. The centrodorsal is small, sub-conical to almost hemispherical, 

 almost entirely covered with well-defined cirrus sockets, of which about the periphery 

 there are 3 beneath each radial. The apex bears some low papillae. 



The cirri are XX-XXXII, 28-30, 10 mm. long, the apical cirri being much shorter 

 with about half the number of segments. In the peripheral cirri the first segment is 

 short, the second is about as long as broad, the third and fourth, which are the longest, 

 are about twice as long as broad, and the following slowly diminish in length, becoming 

 about as long as broad after the eleventh or twelfth. After the fourth or fifth the distal 

 border on the dorsal side begins to rise somewhat, this elevation progressively occupy- 

 ing more and more of the dorsal surface of the segment, and after the fifteenth or 

 sixteenth, occupying the entire dorsal surface and appearing regularly convex in profile 

 so that the dorsal profile of the distal half of the cirri appears to be deeply lobed. These 

 elevations are broad transversely, occupying the entire dorsal surface of the segments. 

 The opposing spine is prominent, terminally situated, in length about equal to the 

 width of the penultimate segment. The terminal claw is rather longer than the penul- 

 timate segment, and it is rather strongly curved. 



The interradial perisomic areas carry several columns of rather small rounded 

 plates, and there is a single column of 4 or 5 similar plates between the 2 arms of each 

 pair. 



The radials are prominent, projecting almost horizontally beyond the rim of the 

 centrodorsal. The JBr! are short, about two and a half times as broad as long, with 



