Miscellaneous. 323 



spicules are composed of numerous concentric coats ; and in one figure 

 he represents the fracture as produced in the centre, showing about six 

 thick layers, each shorter than the preceding ; but all the other breaks 

 are represented short, straight or oblique, like a broken glass rod. The 

 short reflexed hooks on the surfaces of the elongated spicules at the 

 root of the sponge are formed by folds of the siliceous lamina. 



He describes the network as formed of more or less elongated spi- 

 cules united by a siliceous cement, which, like the spicules, is depo- 

 sited in laminae. 



Dr. Claus's plates show that the spicules of this sponge are formed 

 of concentric laminae as are the spicules of Hyalonema — which, 

 I believe, has not before been observed ; and at the same time he 

 shows that the spines on the surface of the spicules are formed in a 

 very different manner from the ring of spines on the spicules of that 

 genus. — J. E. Gkay. 



Sea-Pools in the Friendly Islands. 

 By Dr. Harvey. 



" I walked out on the coral-reef opposite the landing-place [at 

 Tongataboo]. It fringes the whole north side of the island, in some 

 places extending a mile or more from the beach. A great part of 

 the surface was worn and dead, but in the pools the coral was alive. 

 Near the margin of the reefs these pools were numerous and deep, 

 and in them many beautiful corals were growing luxuriantly. They 

 were various — some branching or leafy, others knobby or massive, 

 some bushy, some tree-like, or saucer-shaped or huge disks, some 

 sessile, others on stems. The colours varied from white to brown, 

 purple, green, yellow, flesh-colour, and dull red ; and many reflected 

 rainbow-tints changing with the angle, particularly at the tips of 

 the branches. The water was clear as air ; and through it multi- 

 tudes of little sapphire fishes (Coloto) darted among the coral- 

 branches. Seaweeds were very few, and almost all of the green 

 order, among which were Halimedea and Bryopsis. Starfishes of the 

 long-armed class, Ophiura and Ophiocoma, were abundant ; and a 

 large brown feather-star was frequent under stones. Great, black, 

 ugly sea-cucumbers (Holothuria; or Trepang) were crawling every- 

 where ; I caught at one, which immediately threw out multitudes 

 of long, blue, shiny, slimy threads, that coiled round my fingers : I 

 dropped the brute, but had some difficulty in getting my hand free ; 

 it did not sting me, however. I picked up a Cidaris and an Echinus 

 (Urchin), and saw another species of the latter, which I did not 

 venture to touch, remembering how I had been stung by one (I 

 think the same species) at Key West. It has long, slender, and 

 very brittle spines, covered with highly poisonous slime. Near the 

 edge of the reef Nullipores abound, in places left bare at low water. 

 I noticed that some of the living corals were bare also ; but proba- 

 bly they did not long remain so, for it was a low spring tide. 



" A huge and beautiful species of Alcyonium (a soft coral called 

 ' dead-man's toes ') grew where it was left exposed at low water. 



