new Starfish and new Britile Stars. 117 
Astrodendrum galapagensis, sp. n. 
The disk is 7 mm. in diameter, strongly excavate in the 
interbrachial regions. 
This species appears to be related to A. sagaminum 
(Déderlein), from which it differs in the following parti- 
culars: the granulation of the disk and arms is much 
coarser, the granules being rather widely scattered, so that 
on the disk the major part of the surface is naked integu- 
ment ; the granulation of the interbrachial spaces below is 
closer than in A. sagaminum, and the granules are all sub- 
equal instead of being of two distinct sizes, larger (and 
fewer) and smaller (and more numerous), asin A. sagaminum. 
Beneath, except in the interbrachial spaces, there are 
only a few small and widely scattered granules. 
The first arm-branch appears to consist of eight or nine 
segments, the second of ten. 
Type. Cat. no. 38581, U.S.N.M., from ‘ Albatross ’ 
Station 2818, among the Galapagos Islands, in 392 fathoms. 
Ophiacantha cyrena, sp. 0. 
The disk is 8 mm. in diameter ; the arms are 50 mm, 
long. 
The radial shields are visible just above the arm-bases as 
small broad triangles with the outer angles broadly rounded ; 
their length is less than half as much again as the greatest 
width (which is just within the border of the disk); the 
inner half of the distal border is produced slightly beyond 
the edge of the disk, and is strongly convex; this convexity 
is carried backward for some distance in the inner half of 
the plate; there is a more or less pronounced elevation of 
the median portion of the proximal half of each radial shield. 
The radial shields of each pair are separated interiorly by a 
wedge-shaped mass of plates with only slightly converging 
sides, which at the border of’ the disk is usually about half 
as broad as the length of the distal border of the shields. 
Except for the small radial shields the disk is covered 
with rounded, subequal, overlapping plates, each of which 
bears a short truncated spine arising from an expanded 
circular base ; these spines increase slightly in diameter 
from the bottom to the top, and bear numerous small 
spinules along their sides, which increase in length out- 
wardly and form a prominent thorny crown. Some of the 
scales in the wedge separating the radial shields of each 
pair are much larger than the others, and than those of 
