THE STARFISHES OF THE HAWAIIAN ISLANDS. 
1009 
each, but toward the middle of ray the outer series becomes reduced in size, finally to an odd spine 
which persists on a few plates, and eventually disappears at about the middle of ray. Second series 
persists to tip. In the majority of specimens, on the inner part of ray the actinal spines are grouped 
into a very definite pedicellarian apparatus, conical in shape. These may be confined to plates of the 
basal third of ray, or may extend to the limit of the outer actinal series. Rarely on the outer portion of 
ray a few of the plates haVe the furrow and second series loosely grouped into a similar apparatus. 
On innermost plates bearing the actinal pedicellarise an odd actinal spinelet is present. Sometimes 
there are 5 or 6 actinal spinelets instead of 4. 
Actinal interradial area almost absent. There are about 4 small intermediate plates, each of 
which bears a 4-valved pedicellaria, similar to, but slightly smaller than those of the adambulacrals. 
Mouth plates rather small, elongate, and narrow, with relatively short armature consisting of a 
superficial series of 10 stout, short, tapering, pointed spinelets, arranged along the edge of the median 
suture; subequal, except the 2 or 3 outermost, which are smaller, and the innermost, which forms with 
that of the adjacent plate a pair of longer, tapering, pointed teeth, directed toward actinostome. The 
spinelets of the superficial series are often blunt. A marginal series of 5 to 8 shorter, pointed spinelets 
is placed at a higher level, facing the ambulacral furrow. These are either directed outward into 
furrow, or are appressed against the base of the innermost spinelets of the superficial series. Con- 
siderable variation exists among the specimens in regard to the details of armature, such as the num- 
ber and shape of spinelets, as well as their relative sizes. 
Madreporic body small, partially obscured by paxillae, and situated a little less than its own 
diameter distant from the margin. Striations coarse and rather few in number. 
' Color in life: Paxillar area dull olive brown, the marginal plates dull pinkish yellow, or straw 
color; actinal surface very pale straw yellow. 
Young: The smallest specimen taken (station 4181) has R=7 mm., and r=2.25 mm., and 
besides having relatively shorter arms than the larger examples, differs in details of ornamentation. 
The paxillae lack the central granule, there being about 4 or 5 granules spaced around the margin of 
pedicel. Inferomarginals have but 2 spines. The furrow series of adambulacrals is relatively more 
conspicuous than in the adult, and the central spinelet is less different from the 2 lateral ones. On 
first adambulacral plate there are 4 actinal spinelets, 3 of which form a pedicellaria. On second and 
third plates there are 3 spinelets each, and beyond this point, only 2. A very prominent epiproctal 
elevation is present. All stages between this and the adult are represented in the collection. 
Locality: Type (no. 21144, U. S. National Museum) from station 4116, northwest coast of Oahu 
Island, 241-282 fathoms, coral sand and foraminifera; bottom temperature 48.8°. Astropecten 
pusillulus was taken in greatest abundance off the north coast of Maui, in from 220 to 253 fathoms, on 
gray sand. Nearly 650 specimens have been examined. The following is a complete list of the 
stations: 
. Record of localities. 
Station. 
Locality. 
Depth. 
Nature of bottom. 
3865 
Northeast approach to Pailolo channel between Maui and 
Molokai islands. 
256-283 
Fine volcanic sand, and rocks. 
3918 
South coast of Oahu island 
294-257 
White sand and mud. 
4044 
West coast of Hawaii Island 
233-198 
Fine gray sand. 
4045 
do 
199-147 
Coral sand foraminifera. 
4048 
do 
374 
Fine gray sand, rocks. 
Gray sand. 
4082 
North coast of Maui Island 
220-238 
4083 
do * 
238-253 
Do. 
4084 
do 
253-267 
Fine sand. 
Sand, shells. 
Fine gray sand. 
4085 
do 
4096 
Northeast approach to Pailolo channel 
272-286 
4116 
Northwest coast of Oahu Island 
241-282 
Coral sand, foraminifera. 
4181? 
3472 
Vicinity Kauai Island? 
South coast of Oahu Island 
811-671? 
295 
Probably an error for 4081. 
Fine white sand. (Cruise of 1891.) 
The present species is characterized by its small size, slender rays, unarmed superomarginals, and 
the character of its paxillae and adambulacral armature. It appears to be very distinct from any 
described form. 
