MUSEUM OF COMPARATIVE ZOOLOGY, 35 



AVidth of arm close to disk, without spines, 1.5 mm. Two wide, slender 

 pointed mouth-papillae on each side, standing high up on the jaws. Four 

 teeth, the three upper ones flat and wide, with a curved cutting edge ; the 

 lowest thicker and more conical. Mouth-shields flat and small, of a wide 

 heart-shape with a rounded angle inward and outer edge rounded ; length to 

 breadth .7:1. Side mouth-shields wide without, where they enclose the 

 corner of the mouth-shield, narrow and just meeting within. Under arm- 

 plates pentagonal with inner angle slightly truncated, lateral sides re-enteringly 

 curved, and outer edge straight. Side arm-plates with outer edge swollen ; 

 meeting above, and nearly so below. Upper arm-plates thin and translucent, 

 of a transverse oval shape, about twice as wide as long. Disk smooth, flat, 

 angular and very thin, covered with small, thin, rounded, ill-defined scales. 

 Radial shields with a vague outline, of a bent pear-seed shape, nearly touching 

 without, separated within by an oval of five scales ; length to breadth 2.5 : 1. 

 Scaling on lower interbrachial space finer than that above. Three rather slender, 

 bluntly pointed, tapering, cylindrical arm-spines, a little longer than an arm- 

 joint, well up on the outer edge of side arm-plates. Tentacle-pores large, but 

 without a scale. Color in alcohol, pale gray. 

 Station 198, 2,150 fathoms, 1 specimen. 



Amphilepis tenuis sp. nov. 



Plate XVI. Figs. 433-434. 



Special Marks. — One minute tentacle-scale. One mouth-papilla on each 

 side.* Radial shields short and wide, and joined for half their len^-th. 



Description of an Individual (Station 237). — Diameter of disk 4 mm. 

 Width of arm close to disk, without spines, .7 mm. One wide, pointed, some- 

 what bent mouth-papilla high up on each side the mouth-angle, and a pair, 

 short, thick, and rounded, at the apex. Mouth-shields small, twice as broad as 

 long, of a transverse diamond-shape, with rounded angles. Side mouth-shields 

 three-sided, short and swollen, wider without, tapering rapidly within, where 

 they scarcely meet. Under arm- plates broad pentagonal, with a short angle 

 within, outer side nearly straight, and laterals slightly curved. The first plate 

 is large and of a truncated wedge-form. Side arm-plates meeting broadly 

 above and nearly touching below. Upper arm-plates twice as broad as long, of 

 a nearly semicircular outline, with the curve inward. Disk flat and angular, 

 covered with very thin scales ; in centre of the disk is a rosette of six large ill- 

 defined primary plates, each nearly surrounded by minute scales. Radial 

 shields short, wide pear-seed shaped, joined for the outer half of their length, 

 narrowly separated within by a wedge of small scales. Scaling on interbra- 

 chial space below, much finer than that above. Three short, cylindrical, 

 bluntly pointed arm-spines. One minute, rounded tentacle-scale, which easily 

 falls off. Color in alcohol, faint greenish-gray. 



Station 237, 1,875 fathoms, 1 specimen. 



* Sometimes broken in two, as in the figure. 



