204 BULLETIN 100, UNITED STATES NATIONAL MUSEUM. 



AMPHIACTIS DUPLICATA (Lyman). 



Plate 63, figs. 1-4. 



Amphiura duplicata LYMAN ('74), p. 19, pi. 5, fig. 78; ('79), p. 226; ('82), 



p. 136. KCEHLER ('95), p. 74; ('98), p. 49. 

 Amphiura partita KCEHLER ('96), p. 336, pi. 7, figs. 50, 51; ('99), p. 48; 



pi. 10, figs. 79, 80; ('04), p. 96. 

 Ophiactis duplicata LUTKEN and MORTENSEN ('99), p. 142. KCEHLER ('07a), 



p. 311; ('14), p 40. H. L. CLARK ('15), p. 261. 

 Amphiactis duplicata MATSUMOTO ('15), p. 67; ('17), p. 147. 

 Amphiodia partita H. L. CLARK ('15), p. 248. 

 Amphiactis partita MATSUMOTO ('17), p. 147. 



Localities. Albatross station 5348 ; Palawan Passage ; Point Tabo- 

 nan bearing S. 89 E., 62.08 kilometers (33.5 miles) distant (lat. 10 

 57' 45" N., long. 118 38' 15" E.) ; 685 meters (375 fathoms) ; 

 December 27, 1908; Co., S. 



Five specimens (Cat. Nos. 41053, 41057, U.S.N.M.). 



Albatross station 5475 ; east coast of Luzon ; San Bernardino Strait 

 to San Miguel Bay; San Bernardino Light bearing S. 27 W., 20.38 

 kilometers (11 miles) distant (lat. 12 55' 26" N., long. 124 22' 12" 

 E.) ; 357 meters (195 fathoms) ; June 24, 1909; Sh. 



One specimen (Cat. No. 41055, U.S.N.M.). 



Albatross station 5658; Gulf of Boni, Celebes; Cape Loko Loko 

 bearing S. 31 W., 19.84 kilometers (12 miles) distant (lat. 3 32' 

 40" S., long. 120 31' 30" E.) ; 933 meters (510 fathoms) ; December 

 19, 1909 ;gy. M. 



One specimen (Cat. No. 41056, U.S.N.M.). 



Notes. Following the example of Matsumoto I am placing this 

 species in the genus AmpMactis established by him, the creation of 

 which is abundantly justified by the arrangement of the mouth papil- 

 lae and by the internal structure. 



The specimens are all of small size, and the diameter of the disk 

 does not exceed 5 mm. They agree well with the description which 

 I published of AmpMura partita (pi. 63, figs. 3, 4). The dorsal 

 plates of the disk are rather thick with the borders raised, and 

 sometimes they are even somewhat thickened. The mouth shields 

 in general show the form which I have described and figured in A. 

 partita ('96, p. 336, pi. 7, fig. 51), but I notice some variations; 

 sometimes these shields are as long as broad, and they may even be 

 a little longer than broad, while on other specimens they are shorter 

 and broader, and they thus assume the form which is represented by 

 Lyman and by Liitken and Mortensen in Ophiactis duplicata. Un- 

 der these conditions it does not seem to me to be worth while to 

 maintain the distinction which I had thought it necessary to make 

 between A. partita and A. duplicata, and I believe that the first 

 should be considered as a synonym of the second. 



