82 PROCEEDINGS OF THE NATIONAL MVSEUM. vol. xxxiii. 



20. ANTEDON ISIS, new species. 



Centro-dorsal hemispherical, bearing- 30-40 slender cirri. 10 mm. 

 long, with 20 joints, not especially elongate, the fourth, which is the 

 longest, being little more than twice as long as high; all the joints 

 are expanded distally, slightly overlapping, but do not develop dorsal 

 spines. 



First radials visible at angles of calyx; second radials narrow and 

 much curved; axillaries approximately square, with the sides concave. 

 Ten arms 65 mm. long, very slender; first brachial short, with a long 

 outer and short inner edge; second brachial irregularly quadrate; third 

 and following brachials irregularly quadrate, becoming longer later, 

 and very long and "dice-box" shaped distally; syzvgies in the third, 

 eighth, and twelfth brachials and distally in alternate joints, sometimes 

 with intervals of 2 joints. 



First pinnule 7 mm. long, moderately slender, with about 20 joints, 

 the basal 3 or 4 short, the others longer than wide; the second pinnule 

 somewhat shorter, with about 12 joints, the basal 4 short, the rest 

 longer than wide; third pinnule like the second and of the same length; 

 the fourth and following pinnules bear large genital glands; distal 

 pinnules 9 mm. long, very slender, with 15 joints, the lirst 2 short and 

 expanded, the remainder much elongated. 



Color in life ye41owish brown, the skeleton and cirri lighter. 



Type.^C^iL No. 22617, U.S.N.M.; from Albatross station No. 4917; 

 30° 24' 00" north latitude, 129° 06' 00" east longitude (about 90 miles 

 WSW. of Kagoshima Gulf); 361 fathoms; August 13, 1906. 



21. ANTEDON ARCTICA, new species. 



Centro-dorsal small, liemispherical, bearing about 30 cirri; these 

 are 13 mm. long, with 20 to 25 joints, the longest about twice as long 

 as broad, becoming short and squarish in the distal half; distal 6 or 7 

 joints may or may not have blunt dorsal spines. 



First radials just visible; second radials ver}" short, trapezoidal, 

 more or less incised by the axillary; axillary nearly twice as wide as 

 high. Ten arms, the lirst 9 brachials squarish, then quadrate, longer 

 than wide, becoming more elongate distallv; syzj^gies usually in the 

 third, eighth, and twelfth (sometimes seventh and eleventh or thir- 

 teenth) brachials, and distally at intervals of two joints. The arms are 

 25 mm. long to the twenty-fifth brachial. 



First two pinnules very long (8 mm.) about equal in length, Hagellate, 

 the first with 25 joints, less than twice as long as broad, serrate at 

 the tip, the basal 6 or 7 joints strongly carinate; second pinnule with 

 rather fewer, more elongate joints, also carinate basally, but not so 

 much so as the first; third pinnule much shorter, stouter, with elongate 



