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

344 COLLECTIONS rROM MELANESIA.H(ih. Warrior Eeef and Prince of Walos Channel, Torres Straits ;in the latter case from 7 to 9 fms., bottom sand (actually attachedto a stone).This is a very beautiful and attractive species, the mode ofbranching and the proportions of the branches being gracefuland the colours very vivid.Of the three dry specimens obtained (i.) deep yellow, is 550 millim.(22 inches) high by 325 millim. (13 inches) in extreme diameter ;(ii.) lemon-yellow specimen, 475 by 275 millim. (19 by 11 inches) ;(iii.) reddish specimen, 475 by 387 millim. (19 by \^\ inches). Ayoung specimen preserved in spirit of the same colour as (i.), andmeasuring 145 millim. high by 30 millim. maximum lateral expanse,is distinguished by slenderer habit.Of the doul)le-headed spicules which Verrill has found in manyLeptor/orgice I have seen none here, though sometimes almost deceivedby pieces of broken fusiform spicules, consisting of a smoothmedian portion and a whorl of tubercles left at each end of it. Ihave no doubt as to the specific identity of the above specimens.In the main external features of the corallum, and the forms andproportions of the different kinds of spicules, they agree substantiallywith one another, as may be seen by the few differences bywhich it has been found possible to distinguish the two varieties ;the colour is the only serious difficulty in the way of uniting thesetwo varieties, and is shown not to be of specific importance in thiscase by the fact that red spicules do occur in the cortex of bothspecimens of the yellow variety, and that in that of the mainbranches of the red form there are almost, if not quite, as manyyellow as there are red spicules, some individual spicules beingtransitional in colour.In its manner of branching the species belongs to one of theless common types of this large genus. Of other Australian speciesL. divergens, Studor (MB. Ak. Berlin, 1878, p. 655, pi. iv. fig. 21),from N.W. Australia, is a very different form, if it be a Leptogorgiaat all ; its polype-spicules are very large and the mode of branchingdichotomous. Sydella austmlis, Gray (P. Z. S. 1872, p. 747, pi. Ixiii.figs. 8, 9), from Sydney, only known from a drawing, is perhapsanother Australian Leptogorgia distinguished by a long terminationto the branchlcts bare of cells.c .,„^^ ^ '/ PSAMMOGORGIA, r^rnZ?.17. Psammogorgia rectangularis. (Plate XXXVI. figs. A, a, «''.)Corallum erect, branching in one plane ; the main branches pinnateon one side with short claviform twigs, projected almost atright angles to branches, at intervals of 8 to 20 millim.Stem cylindrical, about 1*25 millim. in diameter. Branchesrather compressed from front to back ; average diameter from sideto side 2 millim. ; diameter of small branches at origin 1 millim., at