40 ‘* BNDEAVOUR ” SCIENTIFIC RESULTS. 
asymmetrical ; they occasionally replace one or more of the 
marginal granules. Papulz numerous, small, single, occurring 
scattered more or less irregularly among the plates ; occasion- 
ally a regular series of 6 surrounds a large plate. Madreporite 
small, about equal to 2 or 3 ordinary abactinal plates, rounded 
triangular, only half as far from centre of disk as from disk 
margin. 
Superomarginal plates about 40 on each side of each ray 
(48 in the largest specimen), those in interradial region nearly 
twice as wide as long, more nearly square at middle of arm and 
then becoming much wider than long again near tip ; all are 
closely covered with granules, similar to but more rounded, and 
the marginal ones at least, distinctly coarser, than those on the 
largest abactinal plates ; there are about 100 on each of the 
superomarginals near the interradius; occasionally pedi- 
cellarie replace granules. Terminal plates small, distinctly 
longer than wide, not deeply notched distally. Infero 
marginals apparently one less on each side of each ray than 
superomarginals, at least in the larger specimens ; the number 
may be the same in the two series, but in many cases the series 
do not correspond exactly along the middle of the arm ; the 
granular covering of the inferomarginals is like that of the 
other series. Actinolateral plates in 8-9 series; the first 
(adjoining the adambulacrals) extends from the oral plates to 
the tenth inferomarginal from the tip of the arm ; the next 
series extends to the twentieth inferomarginal from arm-tip ; 
the next series only reaches the eighth or ninth inferomarginal, 
counting from interradial mid-line ; remaining series irregular 
and of few small plates ; all the plates carry coarse, angular 
granules like those on the abactinal plates, but no pedicellarize 
occur; at least I have seen none. Adambulacral plates 
squarish or rather wider than long, about 60 (in the holotype), 
the inner margin at first straight but becoming decidedly convex 
distally ; furrow margin with a series of 5 or 6 flat, blunt 
spines, rather crowded, nearly equal or the most adoral 
shortest (in the figure [Fig. 3] the spines are too abruptly 
truncate andare too widely spaced) ; externally isa second series 
of 4 shorter, thicker, more angular spines; a third seriesof3or4 
still shorter and thicker spines are borne on the outer margin 
of the plate ; between this series and the second is a rather 
conspicuous bare space; the spines of the third series are 
scarcely to be distinguished from the angular granules on the 
actinolateral plates. Oral plates neither conspicuous nor 
peculiar; the oral spines, especially at tip of jaw, are, however, 
very heavy, more or less prismatic and 2-3 mm. long. Colour, 
