...shell should be opened under water, in order to determine if it contain a gas ; the nature of this gas should likewise, if possible, be ascertained. As a...larger than the Spirula, and its shell external. The towing net should be kept overboard at all practicable periods, and drawn up and examined at stated...

...shell should be opened under water, in order to determine if it contain a gas ; the nature of this gas should likewise, if possible, be ascertained. As a...larger than the Spirula, and its shell external. T,he towing net should be kept overboard at all practicable periods, and drawn up and examined at stated...

...power of rising or sinking in the water. In the event of a living Pearly Nautilus (Nautilus Pompilhts) being captured, the same observations and experiments...been taken by thus sweeping the surface of the sea. Among the floating Mollusca likely to be met with in the tropical latitudes is the Spirula, a small...

...wound the ligamentous border of the shell of the chitons, and not to injure the edges of the limpets. such mutilation would affect its power of rising or...been taken by thus sweeping the surface of the sea ; but unless the towing-net be carefully watched and manoeuvred, it will become filled with every description...

...power of rising or sinking in the water. In the event of a living pearly nautilus (Nautilus Pompttius) being captured, the same observations and experiments...and facility, as the species is much larger than the spi<ula, and its shell external. The towing-net should be kept overboard at all practicable periods,...

...of rising or sinking in the water. In the event of a living pearly nautilus (Nautilus Pom• pilius) being captured, the same observations and experiments...larger than the spirula, and its shell external. The towiug-net should be kept overboard at all practicable periods, and drawn up and examined at stated...