60 BULLETIN 100, UNITED STATES NATIONAL MUSEUM. 



(2.5 miles) distant (lat. 13° 41' 00" N., long. 120° 47' 05" E.), 365 

 meters (200 fathoms) ; January 20, 1908. 



One specimen (Cat. No. 41201, U.S.N.M.). 



Albatross station 5367; Verde Island Passage; Malabrigo Light 

 bearing N. 81° E., 14.83 kilometers (8 miles) distant (lat. 13° 34' 37" 

 N., long. 121° 07' 30" E.) ; 329 meters (180 fathoms) ; February 22, 

 1909 ; S. 



One specimen (Cat. No. 41202, U.S.N.M.). 



Albatross station 5505; Northern Mindanao and vicinity; Ma- 

 cabalan Point Light (Mindanao) bearing S. 31° E., 14.27 kilometers 

 (7.7 miles) distant (lat. 8° 37' 15" N., long. 124° 36' 00" E.) ; 402 

 meters (220 fathoms) ; August 5, 1909. 



One specimen (Cat. No. 41205, U.S.N.M.). 



Albatross station 5522; Northern Mindanao and vicinity; Point 

 Tagolo Light bearing S. 39° W., 11.1 kilometers (6 miles) distant 

 (lat. 8° 49' 00" N., long. 123° 26' 30" E.; 421 meters (230 fathoms) ; 

 August 10, 1909 ; Glob. 



One specimen (Cat. No. 41203, U.S.N.M.). 



Albatross station 5527; between Siquijor and Bohol Islands; Bali- 

 casag Island (C) bearing N. 14° W., 15.20 kilometers (8.2 miles) 

 distant (lat. 9° 22' 30" N., long. 123° 42' 40" E.) ; 717 meters (392 

 fathoms) ; August 11, 1909; glob. Oz. 



One specimen (Cat. No. 41204, U.S.N.M.). 



Notes. — The diameter of the disk varies between 3 mm. and 5 mm. 

 The specimens resemble perfectly those which the Siboga collected 

 among the Sunda Islands. It has seemed to me worth while to give 

 here some photographs of this species, which will show its characters 

 better than my slightly schematic drawings of 1896 and 1899 (pi. 21, 

 figs. 1, 5, 6). 



I also give (fig. 5, pi. 93) some photographs of the club-spines on 

 the dorsal surface of the disk. 



H. L. Clark has described a few unimportant variations among the 

 numerous specimens which he has had from the Japanese seas. 



The type series of O. pentagona came from the Andaman Islands, 

 where the species was discovered by the Investigator in 439 to 686 

 meters (240 to 375 fathoms) ; the Siboga collected it in various locali- 

 ties among the Sunda Islands in from 204 to 827 meters (112 to 453 

 fathoms) between latitude 5° N.-5° S. and longitude 119°-132° E.; 

 H. L. Clark has recorded it from numerous localities in the seas about 

 Japan at depths between 82 and 1,724 meters (45 and 943 fathoms). 



Ophiacantha pentagona must be very widely distributed in the 

 Indo-Pacific region, but I do not believe that it occurs in the Atlantic. 

 The two specimens collected by the Hirondelle in the North Atlantic, 

 which I considered as a variety of O. pentagona and to which I gave 

 the name of O. pentagona var. armata ('98, p. 55), characterized by 



