A MONOGRAPH OF THE EXISTING CRINOIDS 159 



sharply from its relatives. The only other species with which it is likely to be con- 

 fused are Comanthvs timorensis and Coinanthena briareus. 



Description. — The centrodorsal is small, flat, pentagonal, scarcely at all raised 

 above the surface of the radials from which it is separated by narrow subradial clefts. 



There are no cirri. 



The radials are entirely visible. The IBri are united laterally, and are moderately 

 short and broad. The IBrj (a.xillaries) are short, pentagonal, with a sharp distal 

 angle, and are entirely free laterally. In the type specimen the rays usually divide 

 three times, but in one case there are four divisions. The IIBr series are 4 (3 + 4), 

 and the following series are 3 (2 + 3). 



The type specimen has 42 arms which are about 170 mm. in length. The bra- 

 chials are rather short; the first is rather narrow, the following gradually increasing 

 in width to about the twelfth, thence slowly decreasing distally. From the sixth on- 

 ward the brachials are wedge-shaped, after the basal third of the arms becoming 

 shorter wedge-shaped, and soon discoidal. The anterior and posterior arms are of 

 equal length. The dorsal surface of the arms is only moderately rough. 



The first syzygy is between bracliials 1 + 2, and the second is from between 

 brachials 21+22 to between brachials 26 + 27; beyond the second syzygy the inter- 

 syzygial interval is usually from 8 to 11 muscular articulations. 



Pd is 16 mm. long, slender, with a short and poorly developed comb. The 

 pinnules on the succeeding division series are markedly smaller, and only 10 mm. 

 long. Pi is from 8 to 9 mm. long, and is very much more slender than the preceding 

 pinnules. Pa is 5 mm. long. Following Pi and P^ there are a few pairs of pinnules 

 of similar size, and those succeeding become only slightly longer, remaining of the 

 same delicate structure. 



The disk is naked, 16 mm. in diameter. The mouth is radial. 



In alcohol the color is light yellowish brown, with the disk grayish brown. 



Notes. — The specimen secured by the Siboga at station 77 is much smaller than 

 the type. It has about 25 arms which are about 70 mm. long. Of the .si.x IIBr 

 series present, three are 2 and three are 4 (3 + 4). The IIIBr series are all 3 (2 + 3), 

 except for one following a IIBr 2 series, which is 4 (3+4). 



The centrodorsal, though stellate in shape, has not as yet quite sunk to the level 

 of the radials; it bears a few small pits, the remnants of cirrus sockets, on its margin. 



The color in alcohol is yellowish white, the pinnules being yellow green. 



Except for the smaller size and the slightly less developed centrodorsal this 

 specimen agrees well with the type with which it was directly compared. 



In appearance this species bears a very close resemblance to Comantheiia briareus 

 and its allies. 



Localities.— Ch.m& Sea [Hartlaub, 1890, 1891; A. H. Clark, 1912] (1, H. M.). 

 PI. 8, fig. 25. 



Siboga station 77; Borneo Bank (lat. 3° 27' S., long. 117° 36' E.); 59 meters; 

 fine gray coral sand ; June 10, 1899 [A. H. Clark, 1918] (1, Amsterdam Mus.). PI. 8, 

 fig. 26. 



Remarks. — As yet only two specimens of this curious species have come to fight. 



