OPHIURANS OF THE PHILIPPINE AND ADJACENT WATERS. 41 



as the smallest of these individuals, but the plates of the dorsal sur- 

 face of the disk, of which the outlines are more distinct, as well as 

 the tubercles which adorn them, have a slightly different arrange- 

 ment, as may be seen by comparing the photograph which I give here 

 (pi. 6, fig. 5) with the drawing which I published in 1905 ('05, pi. 

 12, fig. 12). Beyond the dorsocentral plate, which is rounded, there 

 is a circlet of five radials a little larger than the latter and irregularly 

 lozenge shaped, separated from the dorsocentral by a circlet of very 

 small plates ; beyond the first circlet there is another circlet of rather 

 large radial plates, each of which separates the two radial shields of 

 each pair. On either side of the group formed by these two large 

 radial plates there are two or three very much smaller plates. The 

 remainder of the interradial space is also occupied by a few plates, 

 which are also very small. All of the large plates bear toward their 

 distal angle a large blunted conical tubercle, and most of the small 

 plates also carry a tubercle of reduced size. These small tubercles are 

 often arranged in such a way as to form a row along the borders of 

 the large primary radial plates. The radial shields are rather small, 

 smaller than in the Siboga specimens, and the two shields of each 

 pair are divergent and widely separated proximally, but approach 

 each other closely distally ; these shields are prolonged along the sides 

 of the first upper arm plate. The two first upper arm plates are not 

 in contact, but are separated by a rather large interval occupied by 

 the side arm plates. The fragmentation of the under arm plates 

 begins beyond the third. The genital slits, which are very distinct in 

 spite of the small size of the specimen, are oval in shape. 



Family OPHIOMYCETIDAE. 



OPHIOMYCES DELATA Koehler. 



Plate 22, figs. 11, 12 ; plate 96, fig. 13. 



Ophiomyces delata Kcehleb ('04), p. 100, pi. 17, fig. 9; pi. IS, figs. 1, 2. — 

 H. L. Clabk ('15), p. 221. 



Localities. — Albatross station 5647; Buton Strait, North Island 

 (S.) bearing S. 87° E., 21.50 kilometers (11.6 miles) distant (lat. 

 5° 34' 00" S., long. 122° 18' 15" E.) ; 949 meters (519 fathoms) ; 

 December 16, 1909 ; gn. M. 



One specimen (Cat. 41321, U.S.N.M.) 



Albatross station 5651; Gulf of Boni, Celebes; Buginkali Point 

 bearing S. 67° E., 38.92 kilometers (21 miles) distant (lat. 4° 43' 50" 

 S., long. 121° 23' 24" E.) ; 1,280 meters (700 fathoms) ; December 

 17, 1909 ; gn. M. 



One specimen (Cat. No. 41320 U.S.N.M.). 



Notes. — The individual from station 5647 is larger than the other, 

 and the arms reach a length of 25 mm.; the disk, which is entirely 



