The porpoises mostly belong in the genus Phocaena, the best 

 known species of which, the Common Porpoise {Phocaena pho- 

 caena), never reaches a length exceeding 6 feet and weighs lOO 

 to 120 pounds. There are some six species. The finless black por- 

 poise constitutes the only other genus with a single species 

 Neomeris phocaenoides. 



All porpoises are dolphins. The Bottle-Nosed Dolphin, Tur- 

 siops truncatus, is sometimes called a porpoise. This is incorrect. 

 Tur slops is a true dolphin, and should not be called what it is not. 



Here we shall be principally concerned with the Bottle-Nosed 

 Dolphin and with the Common Dolphin. The Bottle-Nosed 

 Dolphin has a short, well-defined snout two or three inches long, 

 and is characterized by a prominent fin in the middle of the 

 back. Coloration is dark above and light below. Gestation lasts 

 some ten months, birth is monotocous, and the young are 

 suckled for about i8 months. The tail is delivered first, and the 

 infant, about three feet long and weighing about twenty-five 

 pounds, is immediately quite active, though much in need of the 

 care of its devoted mother. The infant will eventually grow to be 

 between ii and 12 feet in length, and weigh about 300 kilo- 

 grams. Tursiops has an enormously wide range, being common- 

 est along the Atlantic coast of America, from Maine to Florida, 

 and occurs in the Bay of Biscay in the Mediterranean Sea, and as 

 far south as New Zealand. 



The Common Dolphin, Delphinus delphis, is readily recog- 

 nized by its well-defined narrow beak and distinctive coloration. 

 The beak is some 5 to 6 inches narrower and finer than in the 

 Bottle-Nosed Dolphin, and is sharply marked off by a deep V- 

 shaped groove from the low reclining forehead. The Common 

 Dolphin reaches a length up to 8|/^ feet. Its range of distribution 

 is very wide, for it may be met in any temperate or warm sea 

 throughout the world, and occurs at times in vast schools. 



Whether the dolphin of classical antiquity is Delphinus or 

 Tursiops is not usually determinable, although each undoubt- 



