50 BULLETIN 100, UNITED STATES NATIONAL MUSEUM. 



Albatross station 5153; Sulu Archipelago, Tawi Tawi Group; 

 Tocanhi Point bearing S. 27° E., 3.87 kilometers (2.1 miles) distant 

 (lat. 5° 18' 10" N., long. 120° 02' 55" E.) ; 89 meters (49 fathoms) ; 

 February 19, 1908 ; co. S., Sh. 



One specimen (Cat. No. 41131, U.S.N.M.). 



Albatross station 5399; north of Cebu; Tanguingui Island Light 

 bearing N. 70° W., 42.25 kilometers (22.8 miles) distant (lat. 11° 21' 

 45" N., long. 124° 05' E) ; 58 meters (32 fathoms) ; March 16, 1909; 

 Si, Sh. 



One specimen (Cat. No. 41130, U.S.N.M.). 



Notes. — This species is well marked and is easy to recognize. The 

 outlines of the plates are not very distinct in the photographs pub- 

 lished by Doderlein, and I am giving here some photographs which 

 I have taken from Albatross specimens. In two of these (figs. 2, 3) 

 the tentacle scales, of which the shape was correctly shown by Dun- 

 can ('78, pi. 11, fig. 27), may be easily distinguished. Doderlein 

 wrote in 1899 that the tentacle scale is entirely lacking in O . dallasi; 

 this is evidently an error. 



There is some variation in the development of the spinules which 

 terminate the club spines of the dorsal surface of the disk; I have 

 already had occasion to notice this fact in my work on the Sibofja 

 ophiurans ('05, p. 55). 



The type specimen of O. dallasii came from the Korean Sea (lat. 38° 

 N., long. 129° E., 91 meters [50 fathoms]). The species has been re- 

 discovered at Amboina and at Ternate, and the Siboga met with it in 

 many localities among the Sunda Islands at depths between 15 and 

 141 meters (8 to 77 fathoms). The greatest depth at which O. dallasi 

 has been captured is that given above for station 5135, 294 meters 

 (161 fathoms). 



OPHIACANTHA DUPLEX Koehler. 



Plate 16, figs. 7-8. 



Ophiacantha duplex Koehler ('96), p. 352, pi. 8, figs. 66, 67; ('99), p. 60, 



pi. 8, fig. 67; pi. 9, figs. 69, 70.— H. L. Clark ('10), p. 206. 

 (f)Ophiacantha diploa H. L. Clark ('11), p. 207; ('15), p. 198. 

 Locality. — Albatross station 5348; Palawan Passage; Point Ta- 

 bonan bearing S. 89° E., 62.08 kilometers (33.0 miles) distant (lat. 

 10° 57' 45" N., long. 118° 38' 15" E.) ; 686 meters (375 fathoms) ; 

 December 27, 1908; co., S. 



Three specimens (Cat No. 41141, U.S.N.M.). 



Notes.— These are smaller than the type specimen, in which the 

 diameter of the disk was 10 mm. ; in the three Albatross specimens 

 the diameter of the disk does not exceed 5 mm., and the arms, which 

 are entire, are from 30 mm. to 35 mm. in length. I give here two 

 photographs of one of these. 



