MUSEUM OF COMPARATIVE ZOOLOGY. 159 
and a notch without, but are hidden by thick skin. No side or upper arm- 
plates visible, but, on removing the skin, the latter are seen to be small trian- 
gular, and separated by the side plates. Disk round and arched, covered by a 
thick skin which in the centre is irregularly wrinkled. Radial shields like 
long narrow ridges covered with a thick skin and set with small flat grains و‎ 
the brachial and interbrachial spaces have the skin more or less wrinkled, and 
often with a few grains ; the lower interbrachial spaces have the same thick, 
somewhat wrinkled skin. There are on the first three joints three arm-spines ; 
beyond this there are four ; they are short, stout, and microscopically thorny, 
with blunt points, and are covered with thick skin ; the upper spines being 
longest. No tentacle-scales, Color in alcohol, white. 
Station 145, 310 fathoms, 12 - specimens, 
Ophiolebes vestitus sp. nov. 
Plate X. Figs. 255-257. 
Special Marks. — Disk covered by thick skin and set with short stumps, or 
grains, bearing a crown of blunt thorns, Arm-spines short, stout, opaque, 
thorny. Mouth-papille stout, blunt, spiniform. 
Description of an Individual (Station 308). — Diameter of disk 10mm. Length 
of arm 50 mm. Width of arm without spines 2.3 mm. Nine mouth-papillo, 
of which the lateral are stout, blunt, cylindrical, crowded, somewhat movable, 
and with rough ends; the innermost is flat and squarish, like the teeth. 
Mouth-shields small, wider than long, with a lobe without and an obtuse angle 
inward ; length to breadth 1: 1.2. Side mouth-snielas somewhat curved, ex- 
tending beyond mouth-shield, wider without than within, where they meet. 
Under arm-plates pentagonal, with a rounded angle inward. Upper arm- 
plates fan-shaped, with a truncated angle inward. Side arm-plates meeting 
narrowly above and below, projecting but slightly. Disk a little puffed, cov- 
ered by thick skin, and sparsely but regularly beset with short stumps or grains 
bearing a crown of blunt thorns, Six stout, cylindrical, blunt, thorny arm- 
spines ; lengths to that of an arm-joint 1.8, 1.2, 1, .8, .8, .8 :.8. One small, 
narrow, pointed tentacle-scale. Color in alcohol, white. 
A young specimen with a disk of 4 mm. had arms 10 mm, long. The disk- 
stumps were longer, and like very short thick spines. The arm-spines were 
less thorny. In this stage it is very near the Ophiuran described by Ljungman. 
as Ophiactis clavigera, which has the same habits also, and is doubtless the 
young of a form of Ophiolebes, like the present one. It differs in having the 
disk-scales and part of the radial shields naked. 
That O. clavigera is of a novel type is shown by the fact that Ljungman 
considered it an extreme modification of Ophiactis, while Liitken deemed it 
nearer Ophiacantha. 
Station 307, 140 fathoms, 3 specimens. Station 308, 175 fathoms, 7 speci- 
mens. Station 310, 400 fathoms, 1 specimen. 
