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

354 COLLECTIONS FROM MELANESIA.32 millim., consists of a strongly flattened, rather undulating portion,with a midrib 1 to 2 millim. thick running longitudinally down itsmiddle, on each side of which the edges are drawn out so as toform a double-edged knife-like ending, with a maximum breadth of7 millim. ; above, this is united to the hollowed, zooid-bearing partby a cylindrical portion, 20 millim. long and 3 millim. in maximumthickness, apparently solid. Only 10 millim. from the commencementof the zooid-bearing part, a strong tubular branch is given off,and another on the same side only 4 millim. further up the terminaltube, which is considerably bent to one side, and constituteswith the last mentioned branch a true bifurcation, which thus takesplace at only 14 millim. from the commencement of the functionallyactive section of the colony.The colony is thus manifestly young, for the stem is 65 millim.long, Avhile the zooid-bearing part is only 40 millim. long and carriesnear the end of each of its branches one or more narrow spatularor grooved processes from 8 to 15 millim. in length, recalling thosewhich attain so great a development (up to 10 centim. long, Studer)in S. r/rai/i, Studer, and in S. {Solmogorgia) tuhulosa, Genth. Themaximum antero-posterior diameter of the tubular part of the colonyis only 8 millim. The verrucas form a single row on each side ofthe tubes and spatulate processes. The colour differs from that ofthe type specimen of the species in being a dull pale orange, withdark purplish verructe, whereas in that specimen it is for the mostpart (in its present dry condition) a dull umber-brown with a tintof red, with a reddish lateral band including the verrucoe. Thelength of the spatulate processes does not appear to me sufficient toshow any close connection with S. f/rciyi ; and as the spicules agreeessentially with those of the type of iS. tortiiosum, I retain that namefor this specimen as well.As Studer's account of the spiculation of the species appearserroneous in some points, I give herewith the results of an examinationof the type specimen. Cortical spicules :—(i.) Clavate orexcentrically fusiform, covered with coarse, prominent, cylindricaltubercles, often roughened terminally ; size of spicule •21 to -39 by•06 to "12. (ii.) Superficial, short, broad, cj'lindrical, with about 3rude whorls of very prominent ragged tubercles ; size of spicule about•14 by '07 millim. [this spicule is not figured by Studer for the species,but a very similar form is given by him as the axial spicule of yS^. grayi,uader which species is also figured one which differs from (ii.) mainlyin having simpler tubercles]. The white chalky axial mass consistsmainly, if not exclusively, of (iii.) long cylindricals with roundedends, bearing sharp-pointed tubercles at considerable intervals ; sizeof spicule about -38 by -035 millim. The external longitudinalverrucfe-spicules (iv.) are irregularly fusiform or cylindrical, stronglyroughened by prominent closely-set tubercles, and measure about•18 by "07 millim. ; towards the mouth of the verruca these passinto irregular flattened or styliform bodies about -14 millim. longby "017 millim. broad, (v.) The horizontal spicules of the verrucoeare fusiform, tapering gracefully to rounded points, more or lesscurved ; they bear numerous small, smooth, and rounded tubercles