Bbnham. — Stellerids and Echiui(h from the Kerrnadecs. 



149 



scattered over each area. The granulations of the skin of these areas is 

 finer than on the plates. 



Characteristic pedicellariae (those termed by Perrier " pedicellaires en 

 saliere " and by Sladen " entrenched "), in the form of shuttle-shaped pits, 

 are likewise scattered over the whole of these areas in considerable numbers ; 

 I comited as many as 15 to 20 in some areas. They are, however, not 

 confined to these places, but encroach upon the edges of the plates. They 

 are set close together, almost touching, with their long axes in all direc- 

 tions (fig. 11). 



The plates on the disc have the same arrangement as in Ophidiaster 

 ophidianns, as described and figured by Ludwig (1897). The circular 

 madreporite is larger than the interradials, and a little nearer the margin 

 than to the centre. 



The actinal surface is covered by the same skin as the upper surface. 

 The adambulacral plates are separated from the infra-marginals by a 

 single row of small plates (the ventro-laterals), every alternate plate being 

 connected with a marginal by an upwardly directed process, while the 

 other plates are horizontally arranged. Papular areas mth pedicellariae 



Fig. 9. 



oU/ cbs. ^v.L 



Fig. 10. 



Fig. 11. 



Ophidiaster (?) kermadecensis. 



Pig. 9. A portion of the side of the ainbulacral groove, seen from mesial aspect after 

 the removal of the opposite wall (x 4). ad., adambulacral; f.s., furrow- 

 spine ; 5., the granulations of the skin pushmg between the fuiTow- spines. 



Fig. 10. The skeleton of one side of portion of a ray (x 4) after treatment with potash 

 and somewhat Hattened out. ad., adambulacral; a.s., pit for actinal 

 ambulacval spine ; c, connective ; d.l., dorso lateral ; ('./«., infra- marginal ; 

 r, radial ; s.m., supi'a-marginal ; v.l., ventro-lateral. 



Fig. 11. An "entrenched pediecllaria " (much enlarged). 



occur outside the latter. The adambulacral armature presents 2 furrow- 

 spines on each plate, closely pressed against the side of the furrow, with 

 the tips outwardly directed. The granular skin pushes furrowwards be- 

 tween them. The actinal spines are much thicker, shorter, and stouter, 

 and somewhat clavate in form. There is one to each plate. 



As Sladen mentions " super-ambulacral plates " in his diagnosis of 

 Ophidiaster, as opposed to some other genera of the family, I examined into 

 their occurrence here : they exist as short rods passing from the upper 

 surface of the ambulacrals to the ventro-laterals. 



