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

416 COLLECTIONS FROM MELANESIA,or the tubes are almofet level with the edge of a wall-like ridgewhich terminates the sponge above ; margin of tubes simple.Surface of sponge between the coarse inequalities smooth, imperforateto naked eye. Texture in spirit firm but brittle ; colourdull and pale umber-brown.Main skeleton—very loose primary lines of spicules, about threespicules broad, running irregularly towards surface, crossed bysecondary tracts of similar character, 2 or 3 spicules broad, at rightangles to the primaries and about '4 millim. apart. Dermalskeleton—extremely loose tracts of irregularly parallel spicules,3 or 4 spicules broad, surrounding roundish or polygonal areasfrom 'IS to '28 millim. in diameter. Sarcode dense, granular,yellowish brown, containing much foreign material. Spiculessmooth acerate, slighly curved, tapering to fairly sharp points fromcentre, more rapidly towards the ends than near the centre ; size•4 by -019 minim.Nab. Port Darwin, N. coast of Australia, 7-12 fms. ; bottomsand and mud.The vertical and horizontal dimensions of the irregular lobes bothvary from about 12 to 22 millim. The specimens are all broken ;the greatest length represented among the pieces is 60 millim.(2^ inches). By the very slight extent to which the tubes whichchiefly characterize the genus are developed, the species is distinguishedfrom S. dura, Schmidt ; by the large size of the skeletonspicules,from S. aulopora. It has somewhat the general habit of thespecimen figure^ by Schmidt (Atl. Geb. pi. v. fig. 8) for the latterspecies, and of Thalysias suhtnanyidaris, Duch. de Foubressin andMichelotti ; but has a more contort character than the latter, andthe spicules are far larger than those of the former. It is also quitedistinct in habit and spiculation from the form termed Thahjsiastriangularis by Carter (Phil. Trans, clxviii. JD. 287), from KerguelenIsland, the spicules in this being (as I have ascertained from theoriginal specimens, now in the Museum) only '19 to '2 by '014 to•016 millim. in dimensions. In Schmidtia (Isodictya, Bowerbank)mirabilis, Bowerbank, another Indo-Pacific species, the spicules areonly about half the size of the present species, although the habit issimilar.It is perhaps nearly allied to JS. clavata (Balsamo-Crivelli),Esper, by its general habit and large sti'ong spicules ; but those ofthat species, as figured by Balsamo-Crivelli (Atti Soc. Ital. v. pi. iv.fig. 12), are considerably stouter than those of S. variahiUs.52. Amorphina megalorrhaphis.Carter, Ann. 8f May. N. H. (5) vii. p. 368.A remarkable small specimen, which at first sight appears to bepedicillate, with a fusiform head, but is in reality horizontal ingrowth. It is a subfusiform mass, which tapers rapidly to a bluntpoint at one end, runs out as a long narrow cylindrical lobe at theother, and is attached by one side of its thickest part, so that the twoends mentioned project horizontally outwards to right and left of tho