378 BULLETIN 82, UNITED STATES NATIONAL MUSEUM 



than broad. P 3 is 10 mm. long, resembling P 2 , with 15 segments. P 4 and the follow- 

 ing pinnules are 7 mm. long, with 14 segments, P 5 and those succeeding being about 

 as stout as PI. The distal pinnules are 10 mm. long. 



Notes. The specimen from Siboga station 99 is typical, and resembles others at 

 hand from Australia. The color is yellow brown with the cirri and pinnules purple. 



The specimen collected by Dr. Mortensen off Jolo has the arms about 150 mm. 

 long. 



The specimen from Singapore is slightly smaller than the specimens from the 

 Philippine Islands but agrees perfectly with them. The 10 arms are 110 mm. long, 

 and the cirri are XV, 31-34, from 20 to 25 mm. long. The color is a beautiful deep 

 violet, more or less blotched dorsally with pinkish flesh color. 



The specimens coUected by the Albatross in the Philippines and the one from 

 Singapore I originally considered as representing a distinct species, which I called 

 Amphimetra formosa. This species was supposed to differ from A. discoidca from 

 Port Denison, Queensland, in having the lower pinnules with shorter segments of 

 which the basal are usually slightly carinate, and the distal have slightly thickened 

 edges vaguely suggesting an approach to the conditions found in Heterometra crenu- 

 lata; the synartlirial tubercles injormosa were said to arise more abruptly than they 

 do in discoidea, and to be somewhat higher and more prominent. The study of 

 additional material showed that these supposed differences do not hold. 



The three specimens collected by the Danish Expedition to the Kei Islands at 

 Amboina are all large. One has the arms 200 mm. long and the cirri XV, 39-42, 

 about 45 mm. long. Another has the arms 195 mm. long and the cirri XVII, 37-39, 

 40 mm. long. The third specimen is similar to the other two. 



Reichensperger recorded seven specimens from Dr. Merton's station 16 in the 

 Aru Islands. The centrodorsal varies from flat to hemispherical ; if it is flat there is 

 sometimes a small tubercle in the center. The cirri are XV-XXVIII (the last in 

 the largest specimen), 32-42, from 30 to 35 mm. long. From the fifteenth-eighteenth 

 segment onward a prominent dorsal spine is developed. The earliest segments are 

 very short and broad, but from the third onward the relative length increases up to 

 the fifteenth-eighteenth segments, which are almost squarish, though always some- 

 what broader than long. The relative length of the segments then decreases, and 

 usually toward the end of the cirri again increases so that the antepenultimate segment 

 is approximately squarish while the last is visibly longer than broad. The radials 

 are slightly visible. The IBrj are at least three times as broad as long. The IBr 2 

 (axillaries) are at the most twice as broad as long, rhombic, rising on the articulation 

 with the IBrj to a very stout sharp tubercle. An almost equally stout tubercle is 

 found on the articulation between the first two brachials. There are in all cases 10 

 arms, which are 120 to 150 mm. long. The form of the brachials is as described and 

 figured by Carpenter in the Challenger report (=A molleri). P, is about 8-9 mm. 

 long and is composed of 15 or 16 segments of which the two first are almost squarish 

 and the remainder are longer than broad. P 2 is about 11-13 mm. long, with 17-20 

 segments, and is somewhat stouter than P, and P 3 . P 3 is 9-10 mm. long, with 16 

 segments. P 2 and P 3 have the two lowest segments almost squarish as in P 1( and the 

 remainder longer than broad. The pinnules following decrease slowly in length and 

 in the number of their segments (14-10) and again increase in the distal portion of 



