42 BULLETIN OF THE 



Length of arm 18 mm. Width of arm near disk .6 mm. Three mouth- 

 papilla) on each side of a mouth-angle, whereof the two inner ones are small, 

 short, and iilmost conical, while the outer is straight and very wide, extending 

 from the first under arm-plate about two thirds the length of an angle. Mouth- 

 shields three-sided, with rounded angles, bounded without by a curve, and 

 within by a rounded angle ; length to breadth, .2 : .3. Side mouth-shields 

 wide, a little"' broader without than within, where they fully meet. Under 

 ami-plates small, pentagonal, with outer side nearly straight, lateral sides a 

 little re-enteringly curved, and an angle within. Side arm-plates nearly meet- 

 ing above and below, and having a thick, low, spine-crest. Upper arm-plates 

 sm^all, irregular transverse oval, with the inner curve deeper than the outer. 

 Disk rather thick, standing nearly clear of the arms, as is usual in the genus : 

 covered with fine, thin, nearly equal, indistinct scales, whereof most are rounded, 

 but some, near the centre, are angular : there are about 12 in the length of 

 1 mm. where they are finest. Along margin of disk are minute, peg-like, 

 scattered spines, w^iich are not jointed at the base. Radial shields long, nar- 

 row, and closely joined ; length to breadth, .6 : .2. At their outer ends are 

 visible the points of the genital plates, in two little lobes. Three stout, equal, 

 peg-like, very short arm-spines, standing nearly at right angles with the arm. 

 Two minute, longer than broad tentacle-scales standing diagonally with the 

 arm -plate. Color in alcohol, nearly white. 



St. Vincent, Cape de Verde Islands, 7 specimens. 



O. africanum differs from 0. isacanthum in having longer arms, and longer, 

 narrower radial shields ; and iioiw 0. formosa by its wide outer mouth-papilla 

 and longer arms. 



OPHIOPHOLIS MiJLL & Trosch. 

 Ophiopholis japonica sp. nov. 



Plate XIII. Figs. 374-376. 



Special Marks. — Upper disk covered with thin scales and large radial shields, 

 neither of which have grains or spines, except the marginal scales. Five stout, 

 cylindrical, tapering arm-spines. 



Description of an Individual (Station 236). — Diameter of disk 10 mm. 

 Length of arm about 40 mm. Width of arm without spines near disk 2.7 mm. 

 Three or four small, irregular, flat, scale-like mouth-papillae on each side, and 

 a flat clump of short, bead-like tooth-papillae at apex of mouth-angle. Mouth- 

 shields and side mouth-shields somewhat obscured by thick skin. The former 

 are transverse oval, much wider than long ; length to breadth .8 : 1.3. Side 

 mouth-shields small and short, with rounded ends, rather wider within 

 than without, and somewhat bent. Under arm-plates a little wider than 

 long, slightly separated, and with rounded corners. Side arm-plates closely 

 soldered with their neighbors, meeting neither above nor below, rising laterally 



