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

;350 COLLECTIONS FROM MELANESIA.genus. It hag a strong bi'oad base, and tapers rapidly to a pointin view, however, of its bad condition, I reserve further details untilbetter specimens are obtained.Hah. Torres Straits, 10 fms.26. Callipodium australiense.Incrustation very thin, viz. '25 to -5 millim., smooth, varyingfrom dark flesh-colour to dull crimson. Forming either elongatedflattened stolons, 3 to 6 millim. broad, or more concentrated in form,Verrucse 2 to 3 millim. apart ; they may be contracted so much asto present mere monticular swellings "5 millim. high, shoAviiig notrace of octoradiate segmentation, or they may form subcylindricalcolumns 1 to 1"5 millim. high, the octoradiate star occupying theirextremities, the walls of the columns being decidedly grooved longitudinallyalong the lines of the segments. Basal diameter of fullycontracted verrucae '6 to 1*0 millim., of the more expanded formsjust described I'O to 1-25 millim. ; apical diameter of the latterabout 1 millim. Spicules of stolon (i.) :—Fusiform, generally taperingto somewhat slender ends, beset with numerous ( about ten)whorls of prominent tubercles with rounded and minutely tuberculateextremities, the maximum height of the tubercles being about•03 millim., diameter -018 millim. ; five to six tubercles in each ofthe central whorls : average maximum size of spicules "42 by '1millim. (including tubercles), (ii.) Fusiform, tuberculate, the tubei'clesplaced mainly on two opposite sides (i. e. in one plane) ; theends of the spicules are blunt and strongly tuberculate ; the tuberclesare about ten in number down each side of the spicule (some muchsmaller ones on the other faces completing the whorls), but are -042by '035 to -042 millim. in average maximum height and breadthrespectively ; rough and often branched ; average maximum size ofspicule -52 by •]4 millim. (including tubercles), (iii.) Branchedspicules, quadri- to multiradiate, the rays either pointed and smoothat ends, or expanding into fungiform terminations ; a few smalltubercles on sides of arms ; average maximum extension of armsabout '35 millim., diameter of thickest arms or shaft (where present)•04 to -00 miUim.[The larger of these last forms (iii.) are evidently merely exaggeratedforms of (ii,), and these are but unequally developed representativesof (i.).]Hab. Prince of Wales Channel, Torres Straits, 7 fms. ; bottomsand.Obs. This species occurs incrusting a sponge. It differs fromVerrill's species C. pacificum and aureuin in the superior size andmore elongate form of the fusiform spicules and tlie smaller relativesize of their tubercles. No " club " or slender " head " spiculesobserved, as in those species.