PETREL, the name applied in a general way to a group of Birds (of which more than 100 species are recognized) from the habit which some of them possess of apparently walking on the surface of the water as the apostle St Peter (of whose name the word is a diminutive form) is recorded (Matt. xiv. 29) to have done. For a long while the Petrels were ranked as a Family, under the name of Procell- ariidae, and thought to be either very nearly allied to the Gulls, Lañdae, or intermediate between that Family and the Steganapodes ; but this opinion has gradually given way, and it is now hard to resist the conclusion that they have to be regarded as an “Order,” to which the name Tubinares has been applied from the tubular form of their nostrils, a feature possessed in greater or less degree by all of them, and by which each may at a glance be recognized. They have usually been subdivided into three groups or Subfamilies, (1) Pelecanoidinae (or Halodrominae), containing some three or four species known as Diving-Petrels, with habits very different from others of the Family, and almost peculiar to high southern latitudes from Cape Horn to New Zealand; (2) Procellariinae, or Petrels proper; and (3) Diomedeinae, or Albatrosses (cf. Mallemuck, vol. xv. p. 334). Recently, however, the anatomy of the group has been subjected to very close examination by Garrod and W. A. Forbes, the latter of whom has summed up the results obtained by himself and his predecessor in an elaborate essay, forming part ix. of the Zoology of the voyage of the “Challenger,” which shew determinations that differ greatly from any that had been reached by prior systematists. According to these investigators, the Tubinares are composed of two Families, Procellariidae and Oceanitidae, whose distinctness had ...