Specimens of another of the Sepiidæ, the diminutive _Sepiola_ (_S. Rondeletii_)—a veritable Liliputian among cuttles—are sometimes caught in shrimp-nets, and brought to the Aquarium. The mantle-sac enclosing the body of this little Tom Thumb cephalopod is about an inch in length, and in shape like a short wide-bore mortar. The head may be supposed to be the tompion fixed in the muzzle; and where the trunnions would be are two little flat fins of rounded outline. The large goggle eyes seem to be out of all proportion to the size of their owner; but they are, apparently, “all the better to see with,” either to watch for a tender young shrimp coming within arm’s reach, or to perceive an approaching enemy. _Sepiola_, like its comparatively Brobdingnagian relatives, has the faculty of rapidly changing colour, and, if angered or alarmed, its hue is almost instantaneously altered from a pale parchment dotted with pink, to a deep reddish brown. In its habits this little animal differs as much from the sepia as the latter from the octopus. It naturally buries itself up to its eyes in the sand; but as sand is apt to harbour impurities, which in a bowl or tank become corrupt, and generate poisonous sulphuretted hydrogen, the bottom of these receptacles is usually covered with fine shingle. It is most interesting to notice how, in obeying its burrowing propensity, the _Sepiola_ adapts itself to its circumstances, and entirely deviates from its customary mode of procedure. To make a sand pit for its hiding-place, it will direct upon it strong jets of water from its funnel, and thus blow out a cavity in which to seat itself, and allow the disturbed particles to settle over and around it; but, as the pebbles are too heavy to be thus displaced by its blasting apparatus, it removes them, one at a time, by means of its arms, which are large and strong in proportion to its little short body. [Illustration: Fig. 8. Sepiola Rondeletii.] Now and again specimens of the “little squid” (_Loligo media_) are brought in. Their movements are very graceful and pleasing. They are gregarious, like other squids, and keep close together. By the action of their tail-fins, they can either “go a-head” or “turn astern;” and it is very interesting to watch their manœuvres. We once had in one of the tanks four of these “little squids” (which are only about four inches long), and I was much amused by seeing them perform, in a most ludicrous manner, the quadrille figure called _La Trenise_. Three of them ranged themselves side by side, and advanced towards, and retired from a solitary one, who, for some reason, was not received into their rank, but faced them. When they withdrew, stern first, to the back of the tank, the lonely one followed them up with a _pas seul_. But there the similitude ended. He was repeatedly driven backwards to his former position, and was not allowed the privilege of taking his partner with him.