250 BULLETIN 82, UNITED STATES NATIONAL MUSEUM 



The radials are concealed. The IB^ are short and much curved, and the IBr 2 

 (axillaries) are subtriangular, both ossicles being very convex with a rather sharp 

 dorsal ridge. The IIBr series are 4(3 +4), with the first two ossicles very convex at their 

 junction. The IIIBr series, when present, are 2(1+2). The elements of the IBr 

 series and the first two elements of the IIBr series are in close lateral contact with 

 sharp lateral edges and flattened sides. In the middle of the postradial series this 

 feature is continued on to the IIBr axillary and the first five or six brachials, but on 

 the outer sides the IIBr axillaries are prevented from meeting those of adjacent post- 

 radial series by the pinnule of the IIBr 2 , which is placed very near the dorsal surface. 



The 27 arms of the type specimen are 100 mm. long. The first twelve brachials 

 are nearly oblong, and those following are more triangular, gradually becoming longer 

 than broad. 



Syzygies occur between brachials 1+2, and again between about brachials 26 + 27. 

 The distal intersyzygial interval is from 6 to 15, usually from 8 to 11, oblique muscular 

 articulations. 



P D is rather slender, about 8 mm. long with about 30 small, compressed, and slightly 

 carinate segments. The pinnules following are similar, decreasing slightly in size to 

 about P 3 after which the next eight or ten pinnules on each side have the lower segments 

 carinate and expanded on the outer side, with the outer ones more styliform. This 

 feature gradually dies out, and the pinnules become more slender and elongated. 



The disk and brachial ambulacra are well plated. The pinnule ambulacra have 

 well defined side plates which alternate with the sacculi. 



The color in alcohol is light whitish brown with patches of brownish gray. 



Notes. After examining the type specimen in the British Museum I wrote that 

 it resembles those in the National Museum from the Philippines. After studying the 

 same specimen Gislen decided that distincta, assigned by me to the genus Pachylometra, 

 must be referred to Crossometra as it has the cirri arranged in 10 columns. 



In 1908 I described Charitometra smithi from a specimen from Albatross station 

 5123 in the following terms. 



The centrodorsal is thick discoidal or short columnar with the cirrus sockets ar- 

 ranged in 2 rows and roughly in 3 irregular columns in each radial area, though the 

 middle column is sometimes lacking. 



The cirri are XXVII-XXX, 19-22 (usually 20), 20-25 mm. long. The first seg- 

 ment is very short, the second is about twice as broad as long, the third is about as long 

 as broad, the fourth is slightly longer than broad, and the fifth is nearly half again as 

 long as broad. The following segments decrease very gradually hi length, the tenth 

 and following being about as long as their distal width. The segments after the eighth 

 or ninth become rounded carinate dorsally, soon developing rather prominent rounded 

 tubercles situated on the dorsal distal edge. The opposing spine, though prominent, is 

 small, terminally situated, reaching a height equal to about half the width of the penul- 

 timate segment or rather less, its base occupying only the distal third of the segment. 

 The terminal claw is about as long as the penultimate segment, rather stout and moder- 

 ately curved. 



The ends of the basal rays are just visible as more or less irregular tubercles in the 

 angles of the calyx. 



