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pointed, Interbracliial arcs wide and well roimded ; lateral walls highest in 

 the interbracliial arc, decreasing gi'adually towards the end of the ray. 



" Tlie abactinal smiace of the disk and rays is covered with paxillœ of a 

 rather peculiar form, wliich I have not obser%'ed in any other sx^ecies. In the 

 immediate centre of the disk the x^^^iU'i^ are small, crowded, and indivi- 

 dually indistinguishable ; they also diminish greatly in size as they proceed 

 along the ray, but remain perfectly distinct, and though closely placed 

 together, in no way interfere with one another's form by crowding. The 

 largest paxiUa) occm- midway between the centre of the disk and the margin, 

 and at the base of rays. Tliese consist of a comparatively large, convex 

 tabulum, coverd with rather coarse hemispherical gi-anules, having more or 

 less of a mulbeny form, with a fringe-like series at the margin of the 

 tabulum of short, equal, skin-covered papilliform spinelets, all directed hori- 

 zontally. On the large paxiUse there may be from ten to twenty granules 

 on the central area of the tabulum, and from sixteen to twenty in the 

 marginal series. In the medium-sized paxilliTß, beyond the base of the ray 

 and in the neighbom"hood of the margins throughout, there are not more 

 tlian tln*ee or four of the central gi'anules, and eight to ten of the marginal 

 series, wliilst in the smaller paxiUfe on the outer half of the ray there is 

 seldom more than one central gi'anules and seven oi' eight appear to be the 

 nonnal number of marginal spinelets ; in these the membranous inA'estment 

 is even more apparent than on the larger paxillte, and is continuous or 

 united for a considerable distance between adjacent spinelets. Upon the 

 rays the j)axillœ are arranged in remarkably regular, straight, transverse 

 series, which extend uuinteiTuptedly from one series of marginal plates to 

 that on the other side of the ray, traversing the whole paxillar area of the 

 ray. Although there is no formation of a definite median Une, the paxiUfo 

 in the middle of the area on the inner third of the ray are distinctly 

 larger than the others in the same transverse series. 



" The marginal plates are large and remarkably massive, forming a 

 broad border to the abactinal and actinal areas and are well roimded in 

 the lateral wall. The superomarginal plates, thirt}^ or thirty-one in number 

 from the median interradial line to the extremity, have the breadth equal 



