282 BULLETIN 82, UNITED STATES NATIONAL MUSEUM 



series being 4(3+4). The two other specimens had 11 and 14 arms up to 90 mm. in 

 length. The color was dark violet and white, variously divided. 



From between Batu Kapal and Meriri there were two specimens each with 11 

 arms, which in one were 90 mm. and in the other 50 mm. long. The larger specimen, 

 in addition to XI normal cirri, possesses a large number of very small flagellate taper- 

 ing cirri cirri in process of regeneration. 



From Dr. Merton's station XII there are three specimens, two with 13 and one 

 with 16 arms, the arm length being up to 70 mm. The color is the same as in those 

 first described from station 10. 



From Dr. Merton's station 17 there is a strikingly slender regular 10-armed speci- 

 men with the arms 70 mm. long. The cirri are very short and compressed, as in the 

 others, up to 7 mm. long with 16-18 segments most of which from the base outward 

 are feebly spined. The synarthrial tubercles are scarcely marked, and the distal 

 brachials in comparison with the other specimens are broader and less triangular. 

 The color in life was banded dark violet-brown and yellow. 



Remarks. I am not quite sure that Eeichensperger's specimens from the Aru 

 Islands really belong to this species. The description of P 3 certainly agrees much 

 more closely with P 3 in H. producta than with P 3 in H. variipinna, while the number 

 of arms and the size also suggest that species. 



Localities. Canton, China; Werner [P. H. Carpenter, 1882, 1883, 1888; A. H. 

 Clark, 1907, 1912, 1918; Th. Mortensen, 1934] (1, H. M.). 



Amboina; Dr. J. Brock [Hartlaub, 1890, 1891; A. H. Clark, 1907, 1912, 1918]. 



Aru Islands; Dr. H. Merton's station 10; north of Penambulai; 8 meters; stony 

 bottom; April 2, 1908 [Reichensperger, 1913]. 



Aru Islands; Dr. H. Merton's station 13; Sungi Barkai (eastern half); 15 meters; 

 rocky bottom; April 9, 1908 [Reichensperger, 1913]. 



Aru Islands; between Batu and Meriri; 10 meters; March 30, 1908 [Reichen- 

 sperger, 1913]. 



Aru Islands; Dr. H. Merton's station XII; off Mimien; 15 meters; coarse sand; 

 April 8, 1908 [Reichensperger, 1913]. 



Aru Islands; Dr. H. Merton's station 17; Sungi Manumbai (Kapala Sungi); 

 20 meters; rocky bottom; May 5, 1908 [Reichensperger, 1913]. 



Geographical range. Known from Amboina and the Aru Islands. The record 

 from Canton needs confirmation as Canton is more or less of a center for "curios" 

 gathered over a wide area. 



Bathymetrical range. From the shoreline down to 20 meters. The average of 

 6 records is 11 meters. 



Remarks. Hartlaub said that at first sight Antedon brockii resembles Antedon 

 ludovici (that is, Heterometra amboinae) in its black color, its centrodorsal, its cirri, 

 and the form of the brachials. But a comparison of the pinnules serves immediately 

 to differentiate the two species, for the carination so characteristic of the proximal 

 pinnules in H. amboinae is entirely lacking in Antedon brockii. He noted that the small 

 conical protuberances on the disk may represent the soft parts of the lowest pinnules, 

 which have become detached from the pinnules and developed independently. Simi- 

 lar protuberances are found to be strongly marked in the type specimen of LoveVs 

 Hyponome sarsii (=Zygometra microdiscus) in the Hamburg Museum and also on the 



