218 BULLETIN 82, UNITED STATES NATIONAL MUSEUM 



as broad as long. The dorsal surface, except in the lateral thirds, is slightly raised, 

 most prominently hi the median line just within the proximal border and on the median 

 part of the two distal faces, just within the distal borders. The lateral angles are more 

 or less irregular, with a greater or lesser tubercular modification. The lateral edges 

 are more or less cut away, forming, with a similar truncation of the distal angles of the 

 IBri, a prominent water pore. 



There are 14 arms, all in process of regeneration. The IIBr series are all 2 re- 

 sembling the IBr series and with the same water pores, but with the outer edges more 

 irregularly tuberculous. The first two brachials are similar to the elements of the 

 division series, and have water pores ulteriorly and exteriorly between them. The 

 remaining brachials have a smooth and unmodified surface as figured by Carpenter, 

 but this is possibly due to the fact that as yet they are incompletely regenerated. 



The other specimen is essentially similar. There are 16 arms, all the IIBr series 

 being 2. Ah 1 the arms except three, which are broken, are regenerating. The tubercles 

 on the ossicles of the division series and on the first two brachials are not quite so 

 extensive, though slightly more marked. The proximal and distal borders of these 

 segments, except hi the median line, are slightly produced and slightly scalloped, this 

 feature increasing progressively to the margin. The lateral edges are similarly pro- 

 duced and slightly swollen, but nearly straight without tubercular modification. Very 

 narrow transversely elongate slits, scarcely noticeable, mark the position of the future 

 water pores. 



I remarked that these specimens appear to represent Carpenter's robusla, though 

 they are more developed than his type. The chief characteristic of the species is the 

 very long and stout cirri. 



Localities. Menado Bay, northern Celebes (lat. 131' N., long. 124 47' E.); 457 

 meters; Captain Christiansen, Great Northern Telegraph Company, March 12, 1913 

 (1, C. M.). 



Challenger station 192; near the Kei Islands (lat. 549'15" S., long. 13214'15" 

 E.); 256 meters; blue mud; September 26, 1874 [P. H. Carpenter, 1888; Hartlaub, 1895, 

 1912; Hamann, 1907; A. H. Clark, 1907, 1909, 1912, 1913, 1916; Gislen, 1928, 1934] 

 (1, B. M.). 



Sahul Bank [Bell, 1893; A. H. Clark, 1913, 1918]. 



Siboga station 297; off Timor (lat. 1039' S., long. 12340' E.); 520 meters; soft 

 gray mud with a brown upper layer; January 27, 1900 [A. H. Clark, 1918] (2, U.S.N.M., 

 E. 473; Amsterdam Mus.). 



Geographical range. From nothern Celebes southward to the Kei Islands, the 

 Sahul Bank, and Timor. 



Bathymetrical range. From 256 to 520 meters. 



History. In the Challenger report on the comatulids published in 1888 Dr. P. H. 

 Carpenter described and figured Antedon robusta on the basis of a single specimen from 

 station 192. Prof. F. Jeffrey Bell in 1893 inadvertently included a specimen of this 

 species in his record of Antedon patula from the Sahul Bank. Dr. Clemens Hartlaub 

 in 1895 compared the size of Antedon robu-sta with that of his new species A. (Thalas- 

 sometra) agassizii. 



In 1907 I transferred Antedon robusta to my new genus Charitometra, and hi the 

 same year A. robusta was listed by Hamann. On the establishment of the new genus 



