Common Dolphin ; Spotted Dolphin 
and few are the visitors to our seaside resorts who have not 
seen a school of ‘‘porpoises” passing up or down the coast just 
beyond the breakers, their arched backs and pointed fins rising 
at regular intervals above the surface of the waves and disap- 
pearing again, as the animal continues on its undulating course. 
Occasionally with a stronger leap than usual the powerful fluked 
tail is seen above the water and sometimes the entire body is 
exposed. 
Like other members of the family, porpoises are sociable and 
always gather in herds or ‘‘schools” of varying size and in 
this way no doubt they pursue with better effect the mackerel, 
herring and other fishes upon which they feed. 
Often at sea porpoises will associate themselves with some 
passing ship and for miles at a time plunge along close to her 
side, perhaps taking the vessel for some gigantic member of their 
own tribe. I have watched them travelling in this manner for 
long intervals and they kept close to the prow, as if piloting 
the ship on its way and apparently with no thought of the 
scraps or refuse which they might have secured had they been 
following in our wake. 
Several species of similar habits occur in the north Atlantic 
which are described below, while others are found in the other seas. 
Common Dolphin 
Delphinus delphts Linnzus 
Length. 7 feet. 
Description. Beak longer and narrower than in the preceding. 
Colour variable; back, fin and tail black, under parts white, 
sides gray. The black descends on the sides to about the 
middle, and there is a black ring around the eye and a black 
line to the beak. There is usually a dusky band from the jaw 
to the flipper and one or two stripes on the sides. Teeth 47 
to 50 above, and 46 to 5! below. 
Range. Pelagic. Apparently not common on our coasts, but has 
been taken in New York Harbour, Wood’s Hole, etc. 
Spotted Dolphin 
Prodelphinus plagiodon (Cope) 
Length. 7 feet. 
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