34 THE ECHINODERMS OF TORRES STRAIT. 
Sluiter (1889) says that this species is quite active for a sea-star, but the specimens 
seen by me at Mer and at Hilo were quite inert. They were not, however, kept in an aqua- 
rium for any length of time as were the specimens watched by Sluiter. At Mer two 4-rayed 
individuals were found. The smallest specimen seen was only 19 mm. across (R =10 mm.), 
while the largest has R =68 mm. and is thus about 130 mm. in diameter. 
PORANIID£E. 
Habroporina.! 
Stellate, with margin formed as in Asterina by inferomarginal series; superomarginals 
minute, overlying inner end of inferomarginals, each inferomarginal with 2 (rarely 1 or 3) 
sharp, slender, sacculate spinelets. Whole test covered with a moderately thick skin, 
obscuring the plates. Abactinal plates circular and small, or larger and of irregular shape, 
more or less imbricated (the upper edge of a plate overlying the lower edge of the one 
above, or the inner edge overlying the outer edge of one nearer the disk center), not in 
distinct series, either longitudinal or transverse. Papule large, single, scattered on disk 
and on upper surface of rays, nearly to tip. Adambulacral armature in two series: inner 
series of 3 or 4 slender, subequal, somewhat sacculate spinelets, parallel with the furrow; 
outer series of much larger sacculate spinelets, one on actinal surface of each plate. Actino- 
lateral plates imbricating, many with single sacculate spinelets. No pedicellariz. 
Type species: Habroporina pulchella H. L. C. (vide infra). 
This interesting genus differs from Asterope very obviously in the lack of a medioradial 
series of abactinal plates and spines, in the absence of any serial arrangement of the abac- 
tinal plates, in the character of the marginal series of plates and spinelets, and in the spine- 
lets on the actinolateral plates. In some of these particulars it is nearer to Porania, but 
the marginal, actinal, and adambulacral spinelets all afford important differential charac- 
ters. In certain important particulars, Habroporina is notably like certain Asterinidee and 
more abundant material may show that its real position is in that family. The skin- 
covering of the skeleton, the absence of serial arrangement of the abactinal plates, and the 
sacculate nature of the spinelets have deterred me from putting it there. Its characters, 
however, certainly suggest that the Poraniidse would be better placed as Dr. Fisher has 
suggested to me (in litt.) in the Spinulosa rather than in the Phanerozonia. 
Habroporina pulchella.? 
(Plate 4, Figure 2; Plate 24, Figures 2 and 3; Plate 26, Figures 4 and 5.) 
R=19 mm.; r=8 mm.; R =2.37r: Br=9 mm. at base of ray, and 7 mm., 7 mm. from 
tip. In life R was nearly 25 mm., but in killing and drying the shrinkage has been very 
marked. Disk moderately elevated, 4 to 5 mm. high, but more or less flattened; rays 
correspondingly high and yet flattened. Body-margin sharply defined by inferomarginal 
plates, each with 2, rarely 1 or 3, sharp, slender, but sacculate spinelets; in drying, these 
spinelets: have usually been drawn together and often look like a single pointed pedicel- 
laria; they are for the most part erected dorsally or even laid back against the dorsal 
surface. Superomarginals minute, lying at inner end of inferomarginals, often separated 
from each other by still smaller abactinal plates, and hence forming an imperfect and easily 
overlooked marginal series. Entire abactinal surface covered with a smooth skin, without 
spinelets of any kind, in life completely concealing all the skeletal plates. In the smaller 
specimen, from which figure 2, plate 4, was made, this skin is thin and delicate, and when 
* a8p6c=pretty + ™6pwoc=made of tufa, in reference to the colors in life and to the color and surface of 
the dry specimens. 
2 Pulchella=beautiful; of obvious application. 
