236 MR. H. L. CLARK ON SOME 
lateral paxillse near the arm-bases. The arms are rather wide near the tip, 
not tapering so much as in some Chinese specimens. Although I have not 
seen any really intermediate specimens, T think the Australian form is more 
probably a local subspecies than a distinct species. Doderlein himself 
suggests that it should perhaps be considered " nur als eine Lokalform.'^ 
Material from the northern coast of Australia and the southern East Indies 
is essential for a proper solution of the problem. 
Nkcteia macrobrachia *, sp. nov. (PL 13. figs. 5, 6.) 
Diagnosis : Disk small ; arms relatively long and cylindrical. Granulation 
of abactinal plates, near tips of rays, coarse^ crowded, and prismatic; 
actinal granulation noticeably prismatic. Abactinal plates of disk and arm- 
bases less paxilliform and more crowded than in the other members of the 
genus. 
Description of holotype : Bays 5. R=60mm.; r = 17mm. ; Tl = 3'5r. 
Br = 16 mm. Br at middle of ray =10 mm. ; at tip, 6 mm. Disk relatively 
small, only a little elevated ; arms relatively narrow, for the genus, some- 
what flattened basally, but nearly cylindrical or terate for the distal half. 
Abactinal plates on disk and on basal two-thirds or more of rays, large, low, 
flat, more or less irregularly hexagonal with rounded corners, well spaced 
but not widely separated, of dissimilar size ; they are connected with each 
other by heavy radiating ossicles, in the spaces between which arise papulae 
in groups of 4-14. Each plate is covered by a coat of low, move or less 
convex, polygonal granules ; there are about 40-50 on a plate 2-2"5 mm. in 
diameter, besides a marginal series of about 25 distinctly larger granules. 
The maroiiial series of adjacent plates are in close contact even on- disk,, 
except here and there at the angles. Distal part of rays covered by similar 
but coarser granules, quite closely crowded and without indication of 
maroinal series. Madreporite small, about 2 mm. across, situated half-waj^ 
between centre and margin of disk. 
Superomarginal plates about 25, very similar to the abactinal plates in 
covering and appearance ; interradial ones much higher than long ; distally 
and especially close to tip of ray, the superomarginals are so closely crowded 
aoaiust each other, the abactinal plates, and the inferomarginals that they 
can be distinguished only imperfectly. Inferomarginals about 27, but distal 
ones very difficult to make out. The whole distal end of the ray is so closely 
covered with coarse unequal granules that plate limits cannot be distin- 
guished. Intermarginal, and even inframarginal, papillse are evident near 
base of ray. 
* urtKp6s=loiig-f-/3paxici)i' = arm, in reference to the characteristically long- and relatively 
slender arms. 
