1885.] PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 441 



visible to the naked eye. They are perforated by numerous (seventy to 

 eighty or more) small rounded openings, and have a central eminence, 

 composed of several slender processes. Each plate bears a large anchor, 

 its length equal to that of the plate. The shaft of the anchor is round 

 and smooth, narrowed next the expanded end, which is surmounted by 

 several rough or lacerate denticles ; the flukes are long, sharp, smooth, 

 strongly recurved, more than a third as long as the shaft. Many of the 

 anchors project from the skin, and are large enough to be visible to the 

 naked eye. Length, in alcohol, IGO"*"* ; diameter, 10™*°. 

 Station 2111, in 938 fathoms, off Cape Hatteras, 1883. 



Ophiomitra spiuea Verrill. 



Verrill, Amer. Journ. Sci., xxix, p. 153, 1885. 

 Verrill, Report U. S. Fish Com. for 1883, p. 42, 1885. 



A large species resembling 0. valida. Arms five, long and stout; 

 disk five-lobed, indented between the arms ; radial shields moderately 

 large, irregularly ovate, with a small notch in the broad outer end j 

 their inner ends are separated by a wedge of small scales, but the 

 outer ends are in contact, or nearly so ; disk-scales rather small, un- 

 equal, bearing small, low, conical spinules or granules; a few granules 

 on the outer end of radial shields and bases of the arms. Arm-spines, 

 eight or nine at base of arms, long, slender, acute, sharply thorny, aris- 

 ing from prominent side-plates; the middle spines are the largest and 

 roughest; the rows do not meet above at base of arms. Mouth-shields 

 rhombic, with incurved lateral margins ; the inner angle acute, the outer 

 one obtuse or rounded; side mouth-shields thickened, crescent-shaped; 

 tentacle scale rather large, those at base of arm wide, flat, and obtuse; 

 farther out lanceolate and rather acute. Mouth-papillsB numerous, un- 

 equal, rather irregular and crowded at the outer mouth-angles, where 

 they form two or more rows ; in the largest example there are eighteen 

 to twenty, or more, in each angle ; in the smaller one about twelve ; 

 they are mostly rather slender, spiniform, or papilliform, the outermost 

 one wider and more flattened. The larger specimen has the disk liJ^'^ 

 in diameter; the smaller one, ll""™. 



Station 2035 in 2,038 fathoms, 1883, two specimens. 



Ophiacantha fraterna Verrill, sp. nov. 



Verrill, Report U. S. Fish Com. for 1883, p. 43, 1885. 



Disk rounded, rather swollen, with ten slightly raised radial ridges 

 made by the radial shields, which have the outer ends small, a little 

 prominent and naked. The surface of the disk is covered with very 

 small, short, obtuse, rough spinules, terminated by several minute sharp 

 thorns ; usually mixed with these there are many small, rather rough, 

 conical granules, of about the same size. Arm-spines at base of arms 

 about eight, longest on the second and third joints beyond the disk, 

 but the rows are not closely approximated dorsally. The upper spines 

 are long, very slender, acute, and but slightly roughened ; the middle 

 cues are a little thorny ; the lower ones comparatively short. Tentacle- 



