CLARK: PUGET SOUND ECHINODERMS. 
325 
Dermasterias imbricata (Grube). Plate 1. 
There is one small star-fish in the collection, which is labelled 
“Dermasterias imbricata juv., Puget Sound, 1896,” but there are 
no other data with it. It is very dark brown in color and only 14 
mm. across. There is also a single, much larger specimen which is 
clearly a Dermasterias and which is almost certainly Grube’s species. 
As a detailed description and figures of that species do not appear 
to have been published, I give the following description of this 
specimen. 
Rays 5. R : r : : 54 mm. : 18. R = 3 r. Rays rather long, broad at base ; 
interbrachial arcs deep. Abactinal surface rather high (13 mm.), and rays 
not sharply set off from disc. Actinal surface almost flat. Both surfaces 
covered with a thick membrane, without spines anywhere. Membrane con¬ 
tains numerous flattened lime spicules (Plate 4, fig. 4), in the shape of rods or 
perforated plates. Marginal plates almost smooth, without spines or even 
granules of any sort, about 22 in number on each side of each ray. Adam- 
bulacral plates (Plate 4, figs. 2 and 3) with one stout, blunt spine at edge of 
furrow ; near tip of ray there is another spine back of this and the two are of 
approximately equal size. Near tip of ray these spines form two series on 
each side of furrow and are independent of each other, but toward the base the 
outer row disappears and its place is occupied by a ridge of skin without spines. 
The spines of the furrow margin increase in size toward the base of the ray, 
where they reach a length of 2 mm. and are connected with each other by a 
fold of skin and each spine ends in a soft fleshy knob. Membrane of both 
surfaces veiy smooth, thick and tough. No transverse furrows on actinal side. 
Madrepore plate single, about 2.5 mm. in diameter, sunk below the membrane, 
smooth, with irregularly radiating ridges. Papulae numerous, arranged in 
groups of 5 to 17 ; on rays there are 6 longitudinal rows of such groups. There 
are none on the actinal surface. Feet stout, in two rows, yellow in alcohol. 
Color (in alcohol) yellowish brown, duller above ; where membrane is torn off 
the color is a pale reddish purple. 
Solaster endeca decemradiata Brandt. 
There are three large dried specimens and three very small alcoholic 
specimens before me. Of the dried ones, one has the rays about 60 
mm. long, and there are but 9 ; the other two have 10 rays each, 
and these are about 100 mm. long. Of the alcoholic specimens, one 
is 14 mm. across (disc 8 mm.) and has 12 rays, and each adambul- 
acral plate bears 3 spines ; another is 27 mm. across (disc 11 mm.) 
and has only 9 rays, and there are 3 or 4 adambulacral spines; the 
third is 32 mm. across (disc 13 mm.) and has 13 rays, and most of 
the adambulacral plates carry 4 spines. In the light of recent 
