30 BULLETIN 100, UNITED STATES NATIONAL MUSEUM. 



OPHIOPHRIXUS CONFINIS, new species. 



Plate 3, figs. 1-8. 



Localities. — Albatross station 5123; east coast of Mindoro; Mala- 

 brigo Light bearing N. 44° W., 60.23 kilometers (32.5 miles) distant 

 (lat. 13° 12' 45" N., long. 121° 38'45"E.) ; 518 meters (283 fathoms) ; 

 February 2, 1908 ; gn. M. 



One specimen (Cat. No. E. 333, U.S.N.M.). 



Albatross station 5592; Sibuko Bay, Borneo, and vicinity; Silun- 

 gan Island bearing N. 1° W., 11.86 kilometers (6.4 miles) distant 

 (lat. 4° 12' 44" N., long. 118° 27' 44" E.) ; 558 meters (305 fathoms) ; 

 September 29, 1909 ; gn. M. 



One specimen (Cat. No. E. 332, U.S.N.M.). 



Description. — The specimen from station 5123 is of large size, the 

 diameter of the disk reaching 23 mm. and the length of the arms 

 160 mm.; unfortunately, the disk is in poor condition, the dorsal 

 surface has been partially torn away and is more or less out of place. 

 The specimen from station 5592, on the other hand, is in a good state 

 of preservation, but it is much smaller; the diameter of the disk is 

 only 12 mm. ; the arms are somewhat unequal ; the largest reaches 100 

 mm. in length the others being much shorter and narrower. 



The disk is pentagonal and somewhat excavated in the interradial 

 spaces. The flat dorsal surface is covered with a rather thick in- 

 tegument deeply colored a brownish black without the least indica- 

 tion of plates, except for a few extremely small rounded plates here 

 and there between the outer parts of the radial shields and on the 

 arm bases ; these plates are a little more numerous on the individual 

 from station 5123. Each of the radial shields forms a very project- 

 ing narrow and elongated rib carrying half a dozen very strong, 

 thick, elongated, and cylindrical spines with their tips rounded and 

 roughened. The two shields of each pair are parallel or very slightly 

 diverging, and they are widely separated from each other. 



The ventral surface of the disk in the interradial spaces is covered 

 by a thick and very dark integument identical with that on the dorsal 

 surface, without the least indication of distinct plates. The genital 

 slits are very broad. 



The mouthpieces are covered by a very thin fairly transparent in- 

 tegument, light brown in color, under which their outlines appear 

 with a fair degree of sharpness. The mouth shields are small, tri- 

 angular, a little_broader than long, with a very obtuse and rounded 

 proximal angle, lateral angles similarly rounded, and a convex 

 distal side. The acloral plates, which are of average dimensions, are 

 in the form of a crescent with a concave proximal border, a convex 

 distal border, and the angles rounded; they are three times as long 



