514 BULLETIN 82, UNITED STATES NATIONAL MUSEUM 



preceding, about twice as broad as long, with a highly polished surface and low, 

 obscure, broad median dorsal tubercles which become better developed distally. 

 The opposing spine is quite distinct. 



The IBri are partially concealed by the centrodorsal. The IBr2 (axillaries) are 

 relatively long, almost triangular, with a sharp distal angle. The IIBr series are all 

 4 (3 + 4), the IIIBr series are all 2, and the IVBr series are all 4 (3+4). The first 

 segments following each axillary are closely united internally and are somewhat 

 wedge-shaped, the outer side being the longer. 



The 47+ arms are about 100 mm. long. The second brachials are somewhat 

 shorter and more nearly oblong than the first. The first syzygial pair (composed 

 of brachials 3+4) and the next 3 or 4 brachials are also nearly oblong. The suc- 

 ceeding brachials are rather sharply wedge-shaped, nearly twice as broad as long, 

 and overlapping, becoming shorter and less obliquely wedge-shaped after about 

 the thirtieth. 



Syzygies occur between brachials 3 + 4, again from between brachials 14 + 15 to 

 between brachials 21+22, and distally at intervals of from 4 to 10, usually 4 or 5, 

 muscular articulations. 



Pd is slender, except just at the base, and is very long, reaching almost 25 mm. 

 The pinnule on the IVBr series, when present, is somewhat shorter, and Pi is shorter 

 still, though more than 15 mm. in length. Pi is longer on arms arising from a IIIBr 

 series than it is on arms arising from a IVBr series. The pinnules following decrease 

 in length to the third or fourth, which are not especially small. The succeeding 

 pinnules gradually increase in length, and are also stouter, with larger segments, 

 becoming more slender again when the brachials decrease in size. The second-third 

 or -fifth segments of the pinnules borne by the fourth and 5 or 6 following brachials 

 have spinous rounded distal processes, suggesting the condition which is carried to 

 an extreme in Comanthina belli. These are much more distinct on some arms than 

 on others. The lowest pinnules have a tolerably well marked comb which gradually 

 decreases in size and disappears after the seventh or eighth brachial. The comb 

 consists of 12-15 (usually 14) teeth. These are low and rounded, arising gradually 

 and gradually becoming obsolete distally. 



The disk is from 30 to 35 mm. in diameter. The mouth is radial. All of the 

 arms are grooved. 



As described by Carpenter the color of the type specimen, preserved in alcohol, 

 is blackish brown, the skeleton somewhat redder, with a broad white stripe along the 

 mediodorsal line which starts from the centrodorsal and extends outward on to the 

 arms. When I examined this specimen it had faded still further, so that the ground 

 color was grayish brown. 



Notes. — Consul Siemssen's specimen from Fuchow closely resembles the type, 

 but is slightly smaller and less robust. 



The centrodorsal is large, with a strongly concave dorsal pole 3 mm. in diajneter. 



The cirri resemble in general those of Comanthus bennetti. They are 25 mm. 

 long and are composed of 23-25 segments, of which the first 3 are very short, the 

 fifth is about as long as broad, and the seventh-tenth are the longest, slightly longer, 

 though scarcely so much as one-third longer, than broad. The following segments 

 decrease very slowly in length until they become about as long as broad, or slightly 



