THE NAUTILUS. 



Visits to the aquarium, of course, were most interesting, the sea 

 water is stored under the buildings and pumped into the tanks 

 mixed with the proper proportion of air. The visitor entering the 

 darkened corridor is at once struck by the brilliant colors and the 

 great size of the living collection. Surely nowhere, in an aquarium, 

 is there such a wealth of animal life. Let us examine the first tank. 

 It is devoted exclusively to echinoderms. In the center are hun- 

 dreds of feather stars (Antedon rosacea) clinging to dead coral stems. 

 At first sight these appear to be plants on account of their yellow or 

 red plumed arms. Crawling all about are other star fish of bright and 

 somber hues. Here and there is a sea urchin and occasionally a sea 

 cucumber. Tank 3 is devoted to mollusks. Swimming about are 

 several squids (Loligo) which have the curious power of suddenly 

 swimming backwards without the inconvenience of turning around 

 These delicate animals, with transparent bodies, and large eyes only 

 live a few days in captivity. The floor of the tank is strewn with 

 gaping red pectens (P. jacobeus) which I noticed swimming down 

 from a ledge of rock by suddenly opening and closing their valves, 

 an awkward but quick means of locomotion. Clinging to the surface 

 of a rock is a large Umbrella mediterranea and nearby several 

 Haliotis. Several huge Trilonium nodiferus, with their opercula 

 thrown to one side, may be observed slowly moving about on the 

 bottom of the tank. One of the most interesting forms is Aplysia 

 limacina, a large brown sea hare, which crawls about or swims by 

 the aid of its wing-like lateral projections. When stones cov- 

 ered with vegetable matter are brought into the tank the Aplysias 

 immediately bestir themselves and will clean the stones in an hour 

 or two. The longevity of Aplysia in the aquarium may be ascribed 

 to this manner of feeding. Tethys, one of the most beautiful naked 

 mollusks of this region, only lives a few weeks after capture. It 

 swims by violent writhingsof the body from side to side. Aeolis and 

 Doris make up for their small size by brilliant coloring. The 

 delicate forms, many of them pelagic, are kept separated in glass 

 receptacles, partly sunken in the water, the perfectly transparent 

 Pterotrachea, a long thin animal with a curved proboscus and 

 Carinaria, another interesting form rarely live more than a day in 

 captivity. In a similar way are kept the beautiful mushroom-shaped 

 Medusa or jelly fish, which propel themselves by opening and closing 

 the body like an umbrella. The Medusa are also transparent, some 



