The porpoises and dolphins which form the family Delphinidse are in all essential respects toothed whales.[[16]]
[16]. A glance at the classification in the Appendix will explain their relationship to other cetaceans.
The name “porpoise” is usually applied to the round-headed members of the family, while “dolphin” distinguishes those which have pointed snouts or beaks.
The fish (Coryphæna), properly called dolphin, which passes through brilliant changes of color when dying, is often confused with the cetacean because of its name, although, of course, they are not related in the remotest degree. Because of this confusion I seldom use the name dolphin but speak of all members of the group as porpoises.
There are so many species of porpoises that it would not be possible in a book of this character to describe them all; therefore, as with the whales, only those of commercial importance will be considered. Most of the members of this family are small, only the killer whale (see Chapter XVIII) and the blackfish exceeding twenty feet in length.
The white whale, or white porpoise. The skin of this species furnishes much of the “porpoise hide” leather of commerce.
The white porpoise, or white whale as it is more usually called, is not only the most beautiful but also one of the most important members of the family, for it is this animal which furnishes much of the porpoise hide and porpoise oil of commerce.
Like its nearest relative, the narwhal, it is a northern species, seldom being found where the water is far above the freezing point; but during the spring the animals come into the St. Lawrence River by thousands and some remain throughout the summer.
In early June of 1909 I left New York for the little French town of Tadoussac at the mouth of the Saguenay River to study these interesting cetaceans and secure skeletons and plaster casts for exhibition in the Museum.