147 
a- c. b. 
Fig. 23. Amphiiira alba Mrtsn. — a. Part of oral side, b. of dorsal side; c. two arm- 
* joints from middle of arm, dorsal side. 
rather broad, not quite as long as half the disk radius; they are 
ir 
diverging and may be separated by a narrow wedge of scales or 
^ join in their outer part. The outer oral papilla broad, but pointed, 
thus evidently of the spiniform type. The oral shields are about 
^ spear-shaped, somewhat longer than broad. Adoral plates just meet¬ 
ing within, sometimes excluded from the genital slit. The ventral 
1 plates are distinctly broader in their outer part, the outer edge being 
t slightly concave. One small triangular tentacle scale. The dorsal 
plates are broadly contiguous, with the aboral edge slightly con- 
vex; they are distinctly broader than long. The basal armjoints 
I 
I carry 6 short siender spines; farther out the number diminishes, 
as usual, to 5—4, and 3 at the end of the arm. They do not 
k 
27. Amphiura alba n. sp. 
Figs. 23, a—c. 
Colville Channel, 35 fms; sandy mud. 21/XI1.14. 4 specimens. 
Diameter of disk 4 mm; length of arms 4—5 times the dia¬ 
meter of the disk. The scales of the disk on the aboral side fairly 
large, those on the oral side much finer, but forming a complete 
covering. The primary plates not very distinet; the radial shields 
10 * 
