OPHIURANS OF THE PHILIPPINE AND ADJACENT WATERS. 53 



The tentacle scale is small and elongated; it is oval on the first 

 segments, then its extremity becomes pointed and furnished with a 

 few very fine asperities. The pores of these two first pairs possess 

 two scales. 



The color of the dorsal surface of the disk and of the arms is a 

 brownish gray ; the ventral surface of the disk is of the same color, 

 but the ventral surface of the arms is very much lighter and simply 

 grayish. 



Affinities a/ad distinctive features. — Ophiacantha graphica appears 

 to be closely related to O. longidens Lyman; the armature of the disk 

 is identical with that which that author has described, and which I 

 also have found in the specimen from station 5153 which I have 

 recorded below and have referred to O. longidens. But our species is 

 sharply distinguished from the latter by its more numerous and rela- 

 tively very long arm spines, which on the first arm segments form 

 rows approaching each other very closely in the dorsal median line 

 and almost joining behind the upper arm plates. It is well to re- 

 mark that the number of these spines reaches six in a specimen in 

 which the diameter of the disk does not exceed 3 mm., while in 

 Lyman's type specimen, as well as in the specimen from station 5153, 

 in which the disk reaches 4 mm. in diameter, the number of the arm 

 spines is eight only. The mouth papillae, which are sometimes three, 

 sometimes four, in number, are shorter than in O. longidens; the 

 mouth shields are triangular, higher, and less broad ; the under arm 

 plates especially are less broad and more elongated; they rapidly be- 

 come as long as broad and even a little longer than broad; the small 

 tentacle scale shows a tendency to become spiniferous, and there are 

 two of them on the pores of the two first pairs. 



OPHIACANTHA LEGATA, new species. 



Plate 17, figs. 4, 5. 



Locality. — Albatross station 553(5; between Negros and Siquijor; 

 Apo Island (C.) bearing S. 26° W., 21.87 kilometers (11.8 miles) 

 distant (lat, 9° 15' 45" N., long. 123° 22' 00" E.) ; 510 meters (279 

 fathoms) ; August 19. 1909; gn. M. 



One specimen (Cat. No. 11373. U.S.N.M.). 



Description. — The disk is 4 mm. in diameter, and the arms are 18 

 mm. long. 



The disk is rounded. The dorsal surface is covered by closely 

 crowded, rather long but thick and stout club-spines, each terminated 

 by three or four short, conical and unequal spinules; the stalk of 

 these club-spines may also show one or two small denticulations, 

 The plates which bear these club-spines are not visible on accouni 

 of their being so close together. For the same reason only the distal 



