NO. l(i<;,s. .1 \IJW (ll'JMS OF IXSTALKI'JD (HI SOI Dti— CLARK. 357 



Arms 10, about 80 mm. long ; first brachial very short, oblong, about 

 four times as broad as long, united basally Avith its fellow, diverging 

 at approximately a right angle distally; second brachial usually 

 about twice as large, wedge-shaped; third and fourth brachials 

 (syzygial pair) somewhat longer than broad; following brachials 

 very obliquely wedge-shaped, at first about as long as broad, but 

 almost innnediately becoming longer than broad and gradually in- 

 creasing in length, being terminally two or three times as long as 

 broad, or even longer, Avith expanded ends; after about the sixth 

 the brachials develop strongly produced and overlapping distal ends, 

 which are armed with a row of comparatively coarse spines. Syzygies 

 occur between the third and fourth brachials, again between the 

 thirteenth and fourteenth, and distally at intervals of two oblique 

 nniscular articulations (" in alternate joints "). . 



Mouth central and very large; anal tube small and marginal; disk 

 naked, except for the previously mentioned interprimibrachial plates. 



Xo pinnules on the fifth to the tenth brachials, PP^, 3, ^, b, ,, d, 

 being absent; P^ 4 mm. to 4.5 mm. long, with twenty joints, slender, 

 and tapering evenly distally; first joint not so long as broad, second 

 and third about as long as broad, the remainder about half again as 

 long as broad; the joints are somewhat constricted centrally and have 

 expanded and overlapping distal ends which are armed with fine 

 spines, and a finely spinous dorsal surface; terminal comb very 

 prominent, composed of six to eight large teeth, trapezoidal or blunt 

 triangular, their bases in contact, somewhat higher than the trans- 

 verse diameter of the joint which bears them, and recurved; Pa sim- 

 ilar to Pj ; P5 (the next pinnule) 3 mm. long with twelve joints, the 

 first two not so long as broad, the third about as long as its proximal 

 diameter, the remainder somewhat longer than broad ; all but the 

 first liave greatly expanded distal ends, armed with comparatively 

 coarse spines; a very round and prominent genital gland is found on 

 the second-fourth or second-fifth joints; following pinnules slowly 

 increasing in length, the joints, except the two first, slowly becoming 

 more and more elongated ; distal pinnules about 4.5 mm. long, or 

 about the length of the oral pinnules; the genital glands are found on 

 three to six pinnules on either side of the arm and are alwaj^s small 

 and situated basally, like that on the first genital pinnule; large side 

 plates are developed along the sides of the pinnule ambulacra of the 

 third and following joints, becoming more perfect distally. 



Color (in spirits). — Brownish white, the perisome yellow brown; 

 probably yellow in life. 



Type.— C2it. No. 254G0, U.S.N.M., from Albatross Station No. 

 2670 ; between the Bahama Islands and Cape Fear, North Carolina ; 

 280 fathoms. 



