NO. 1561. NEW UNSTALKED CRINOIDS— CLARK. 151 



two or more rows of ver}' fine teeth; there is a slight rounded tubercle 

 on the junction of the first two brachials; syzygies occur in 4he third 

 brachial, ag;iin about the eighth or ninth, and usually in the twelfth 

 or thirteenth, with others distally at intervals of 5-7 joints in the 

 proximal part of the arm and 3 joints toward the tip. 



The first pinnule is on the second distichal and reseml)les that on 

 the second brachial; pinnule on second brachial 8 mm. long, of about 

 28 joints, flagellate, the second to the foiu'th joint furnished with large 

 dorsal keels; the pinnule on the fourth brachial is 11-15 mm. long, with 

 35-10 joints, flagellate, the first 2 or 3 joints with a dorsal keel; the 

 pinnule on the sixth brachial is 12-16 nmi. long, with about 40 joints; 

 that on the eighth is about the same, that on the tenth slightly shorter, 

 like that on the twelfth; from this point the pinnules gradually 

 decrease in length and ])ecome more slender, the joints much more 

 elongate; the pinnule on the fortieth brachial is 9 mm. long, with 23 

 long and very slender joints. 



The color in life is brilliant 3"ellow, the arms broadly banded with 

 bright red; the cirri are dull orange red, 



Ti/j)e.— Cat. No. 22631), U.S.N.M.; from Alhatr<m station No. 4880; 

 34^ 16' 00" north latitude, 130^ 16' 00" east longitude (Korean Straits); 

 59 fathoms; August 2, 1906. 



This species is readily distinguishable from A. hartlauh! by having 

 fewer arms, which are longer and more slender, by having the second 

 radials visible, and b}^ the character of the cirri, which are more 

 numerous, stouter, with shorter joints, and with a prominent opposing 

 spine on the penultimate. The very brilliant and unusual coloration 

 may be a good specific character. 



29. ANTEDON THETIS, new species. 



Centro-dorsal discoidal, bearing about 12 marginal cirri; these are 

 about 10 mm. long, with 25 to 30 joints, of which the fourth, fifth, and 

 sixth are squarish; the others wider than long, developing prominent 

 spines distally. 



First radials very short; but laterall}" they are in apposition, form- 

 ing a large interradial triangle, produced anteriorl3% separating the 

 second radials; second radials rather short, trapezoidal; axillaries pen- 

 tagonal, less than twice as wide as high; the second radials and axil- 

 laries are rounded laterally, and widely separated. Ten arms 30 nmi. 

 long; the first brachials on each arm in close apposition for their entire 

 length, roughly oblong; second brachials squarish, strongly convex 

 exteriorly; third brachials longer than wide, constricted in the middle; 

 following 2 or 3 brachials quadrate, then becoming triangular, longer 

 than wide, the outer side convex, ))ecoming elongate and quadrate 

 distally. 



First pinnule small, short, and weak, witii al)()ut 25 sciuarish joints; 



