ve teeth in both jaws,
numerous and conical, broad and high cranium, nasal passages
vertical, no caecum. They are gregarious in habit, carnivorous and
extremely swift, but they must not be confounded with the dolphin
of sailors, which is a true fish (_Coryphaena hipparis_) of great
velocity and brilliant colours, which change like rainbow tints when
the fish is dying. I have several times in vain tried to catch the
fleeting shades with both oil and water-colours, but without
success; for within a few minutes they change from the most vivid
of greens and blues to a pale silvery grey. The true dolphin, of which
we are treating, is the dolphin of the ancients, represented in all
the old pictures and sculptures. They have a medium dorsal fin, and
the pectoral flippers are about two-thirds longer than the breadth.

[Illustration: 1. Gangetic Dolphin--_Platanista Gangetica_. 2.
Round-headed River Dolphin--_Orcella brevirostris_. 3. Gadamu
Dolphin--_Delphinus Gadamu_. 4. Freckled Dolphin--_Delphinus
lentiginosus_. 5. Black Dolphin--_Delphinus pomeegra_.]

NO. 260. DELPHINUS PERNIGER.
_The Black Dolphin_ (_Jerdon's No. 142_).

HABITAT.--Bay of Bengal.

DESCRIPTION.--"Twenty-six teeth on each side above and below, obtuse,
slightly curved inwards; of a uniform shining black above, beneath
blackish."--_Jerdon_.

SIZE.--Total length, 5 feet 4 inches.

This species was taken in the Bay of Bengal and sent to the Asiatic
Society's Museum by Sir Walter Elliot, but it does not appear to be
mentioned by Professor Owen in his notice of the Indian Cetacea
collected by Sir Walter Elliot.

NO. 261. DELPHINUS PLUMBEUS.
_The Lead-coloured Dolphin_ (_Jerdon's No. 143_).

HABITAT.--Malabar coast.

DESCRIPTION.--Thirty-six teeth in each side in the upper jaw and
thirty-two in the lower jaw; of a uniform leaden colour, with the
lower jaw white.

SIZE.--About 8 feet.

Whether this be the same as or a different species to the next I am
unable to say, as the description is meagre, and the number of teeth
vary so much in the same species that no definite rule can be laid
down on them.

* * * * *

The following are the species named by Professor Owen and collected
by Sir Walter Elliot.

NO. 262. DELPHINUS GADAMU.

NATIVE NAME.--_Gadamu_.

HABITAT.--Madras coast.

DESCRIPTION.-Body fusiform, gaining its greatest diameter at the
fore-part of the dorsal fin, decreasing forward to the head by