Report on the zoological collections made in the Indo-Pacific Ocean ...

ECHINODERMATA. 161line of junction of the second and third. Distichals 2 ;palmars 2 :in neither case is the axillary a syzygy, and in both cases there is aslight conical protuberance where the two joints meet, and in bothcases also the more proximal of the two joints is in close lateralcontact with its fellow. First brachials a little wider along theirouter than their inner side ; along the latter they are again in closecontact with their fellow ; as the second brachial is also widerwithout than within, there is a feebly-marked diamond-spaceinterval. The third brachial is nearly oblong, and, being syzygial,has somewhat the appearance of a dice-box. For the next threeor four joints there is no wedge-shaped arrangement ; at firstfeebly indicated, it rapidly becomes more marked ; further out itdiminishes, and the terminal joints are nearly oblong. As inA. jlageUata (see Carpenter, Notes Leyd. Mus. iii. p. 183), theearlier brachials are flattened on their outer side.The first syzygy is on the third brachial, the next about thefifteenth, and there are then intervals of 9-10 joints between thesyzygies.The species is at once to be distinguished from A. Jlagellata bythe fact that the third is shorter than the first pinnule ; of the firstthree the second is the longest. The first is on the second brachial,and is but little shorter than the second ; the first three pinnulesall have broad basal and elongated distal joints, but though longerthan the next succeeding they are by no means remarkable in theirlength.Colour : brownish flesh-coloured arms ; the peristome very muchdarker ; the cirri much darker on their ventral than their dorsalaspect.Disk incised, with a diameter of 7*5 millim. ; arms about80 millim. long ; cirri 21 millim. long.Thursday Island.12. Antedon irregularis. (Plate XIII. figs. A, a-c.)Centrodorsal fiattened, small ; cirri marginal, in two rows, about25 in number (but there may be not more than 15), with 30-35joints, the lowermost short, fourth to ninth longer than wide, thenagain shortening ; no spine, except on the penultimate joint, andthat exceedingly small.First radials not (or barely) visible ;second wide, in contact,with a median convex protuberance ; the third almost perfectly triangular.Arms 11-22. Three joints in the first division, the axillariessyzygies ;when there is a second division there are two joints, theaxillaries not syzygies. The earlier joints of the arm have a wellroundedconvex dorsal surface and are broader than long ; soon,however, they become very markedly wedge-shaped and form aprominent projection alternately on either side. Towards the endof the arms these disappear.