504 BULLETIN 82, UNITED STATES NATIONAL MUSEUM 



finely lobate, and the cirri arise from the depressions between the lobes. The center 

 of the dorsal surface is slightly hollowed. 



The cirri are IX, in a single incomplete row, from 0.5 to 2.5 mm. in length. They 

 are indistinctly segmented and of very juvenile appearance, without any trace of 

 dorsal spines or a terminal claw. The number of their segments is about 10. 



The radials are almost or quite concealed. The IBr! are trapezoidal, proximally 

 twice and distally three times as broad as long. They are entirely united laterally 

 and, according to Gisle"n, are united to the IBr 2 by syzygy. The IBr 2 (axillaries) 

 form right-angled triangles. The IIBr series are 4 (3 + 4). The IIBr,, like all the 

 ossicles immediately following axillaries, are interiorly united. The IIBr 2 are almost 

 rectangular, but are longer exteriorly than interiorly. The IIBr 3 are narrow and 

 bandlike, five times as broad as long. The lateral borders of the IIBr series are 

 straight exteriorly and slightly concave interiorly. The IIIBr series are 2 or, accord- 

 ing to Gislen, 2 (1 + 2). The 3 IVBr series present are 4(3 + 4). 



The arms are more than 39, probably 42, in number. The anterior arms are 

 about 105 mm. in length and the posterior are 80 mm. All of the arms except some of 

 the posterior are provided with ambulacral grooves. The earlier brachials, about 

 the first 7, are short and oblong, those following being irregularly wedge-shaped with 

 produced distal ends. 



Syzygies occur between brachials 3 + 4, again at about the tenth and fifteenth 

 brachials, and distally at intervals of about 6 muscular articulations. 



PD is 15 mm. long and is composed of 35-40 segments which are more or less 

 obscured by perisome. PI is 13 mm. in length and P 2 is 8 mm. P 3 to the fifteenth or 

 nineteenth pinnule have about 25 segments which are as long as broad. These 

 pinnules are thick and stout and have the proximal two-thirds very much distended 

 by the sexual products. The distal 7 segments are provided with stout hooks, 3 on 

 each segment. The other segments have smaller and more irregularly arranged 

 spines. The twentieth and following pinnules are again more slender, 11 mm. long 

 and composed of abut 25 segments which are very long, as much as three times as 

 long as broad, at least in the proximal portion. The distal hooks are only developed 

 on the last 3 segments. The earlier pinnules are provided with a short comb con- 

 sisting of about 6 large teeth. Both among the genital and distal pinnules terminal 

 combs with 6-10 teeth appear here and there. 



The disk carries small calcareous granules. The mouth is marginal. The anal 

 tube is central and inflated. 



The color in alcohol is brown, with dorsally yellow spots on the division series and 

 two yellow bands along the arms. 



Six specimens collected by Dr. Laurence E. Griffin in the Philippines seem to 

 belong to this species, although the cirri are better developed than usual. They may 

 perhaps be best considered as intermediate between this species and the next, though 

 nearer the former. 



One has 39 arms which are 145 mm. long; the cirri are III, 14. Another has 

 about 40 arms, with the cirri VIII, 14; a third has about 40 arms, with the cirri X; 

 a fourth has about 40 arms. One of the remaining 2 has III cirri. 



Remarks. Gislen referred Mjoberg's specimen to Comaster typica on account 

 of the construction of the centrodorsal and the development of the cirri. He said 



