THIS common species is more frequently met with than many others, because it prefers shallow water, and often lives high up among rocks which are only covered by the sea at very high tide; so that the creature can, if it will, spend but a short portion of its time immersed. When uncovered by the tide, it gathers up its leathery tunic, and presents the appearance of fig. 1 _a_. When under water it may often be seen expanding its flower-like disk and moving its feelers in search of food. These feelers have a certain power of adhesion, and any not too vigorous animals which they touch are easily drawn towards the centre and swallowed. Around the margin of the tunic are seen peeping out between the tentacles certain bright blue globules looking very like eyes, but whose purpose is not exactly ascertained. Fig. 1 represents the disk only partially expanded. BUNODES CRASSICORNIS. _Pl._ VI. _fig._ 2. This genus of Actinioid zoophytes is distinguished from Actinia proper by the tubercles or warts which stud the outer covering of the animal. In B. gemmacea these warts are arranged symmetrically, so as to give a peculiarly jewelled appearance to the body. Being of a large size, the tentacles of B. crassicornis exhibit in great perfection the adhesive powers produced by the nettling threads which proceed from them. CARYOPHYLLÆA SMITHII. _Pl._ VI. _fig._ 3. This figure is to show a whiter variety, with the flesh and tentacles fully expanded. PLATE VIII. MOLLUSCA. NASSA RETICULATA. _Pl._ VIII. fig. 2, _a_, _b_, _c_, _d_, _e_, _f_ A VERY active Mollusc, given here chiefly on account of the opportunity afforded by the birth of young fry in Mr. Lloyd’s tanks. The _Nassa_ feeds on small animalcules, for which, in aquaria, it may be seen routing among the sand and stones, sometimes burying itself among them so as only to show its caudal tube moving along between them. A pair of Nassæ in Mr. Lloyd’s collection, deposited, on the 5th of April, about fifty capsules or bags of eggs upon the stems of weeds (fig. 2 _b_); each capsule contained about a hundred eggs. The capsules opened on the 16th of May, permitting the escape of rotiferous fry (fig. 2, _c_, _d_, _e_), not in the slightest degree resembling the parent, but presenting minute nautilus-shaped transparent shells. These shells rather hang on than cover the bodies, which have a pair of lobes, around which vibrate minute cilia in such a manner as to give them an appearance of rotatory motion. Under a lens they may be seen moving about very actively in various positions, but always with the look of being moved by rapidly turning wheels. We should have been glad to witness the next step towards assuming their ultimate form, but were disappointed, as the embryos died. Fig. 2 _f_ is the tongue of a Nassa, from a photograph by Dr. Kingsley. FOOTNOTES