Note 16 — Chapter II
Reading edition
How will this accord with the geographical distribution of the mollusca by Péron and Leseur? After studying the Holothuria Medusæ, and other congeners of delicate and changeable forms, they came to the conclusion that each kind has its place of residence determined by the temperature necessary to support its existence. Thus, for example, they found the abode of Pyrosoma atlanticum to be confined to one particular region of the Atlantic Ocean.—Voy. aux Terres Aust. tom. 1, p. 492, quoted in Lyell’s Principles of Geology, vol. ii. pp. 111, 112.