is a specimen of a plank of oak,
pierced by a sword-fish, and still retaining the broken weapon.]

In the seas around Ceylon sword-fishes sometimes attain to the length of
twenty feet, and are distinguished by the unusual height of the dorsal
fin. Those both of the Atlantic and Mediterranean possess this fin in
its full proportions, only during the earlier stages of their growth.
Its dimensions even then are much smaller than in the Indian species;
and it is a curious fact that it gradually decreases as the fish
approaches to maturity; whereas in the seas around Ceylon, it retains
its full size throughout the entire period of life. They raise it above
the water, whilst dashing along the surface in their rapid course; and
there is no reason to doubt that it occasionally acts as a sail.

The Indian species (which are provided with two long and filamentous
ventral fins) have been formed into the genus _Histiophorus_; to which
belongs the individual figured on the next page. It is distinguished
from others most closely allied to it, by having the immense dorsal fin
of one uniform dark violet colour; whilst in its congeners, it is
spotted with blue. The fish from which the engraving has been made, was
procured by Dr. Templeton, near Colombo. The species was previously
known only by a single specimen captured in the Red Sea, by Rueppell, who
conferred upon it the specific designation of "_immaculatus_."[1]

[Footnote 1: Trans. Zool. Soc. ii. p. 71. Pl. 15.]

[Illustration: THE SWORD FISH (MISMOPHORUS IMMACULATUS).]

AElian, in his graphic account of the strange forms presented by the
fishes inhabiting the seas around Ceylon, says that one in particular is
so grotesque in its configuration, that no painter would venture to
depict it; its main peculiarity being that it has feet or claws rather
than fins.[1] The annexed drawing[2] may probably represent the creature
to which the informants of AElian referred. It is a cheironectes; one of
a group in which the bones of the carpus form arms that support the
pectoral fins, and enable these fishes to walk along the moist ground,
almost like quadrupeds.

[Footnote 1: [Greek: Podas ge men chelas e pterygia.]--Lib. xvi. c. 18.]

[Footnote 2: The fish from which this drawing of the _Cheironectes_ was
made, was taken near Colombo, and from the peculiarities which it
presents it is in all probability a new and undescribed species. Dr.
GUeNTHER has remarked, that in it, whilst the fi