regularly brought from neighbouring lakes to the Mexico
market, its flesh being agreeable and wholesome. Francisco Hernandez
(1514-1578) has alluded to it as _Gyrinus edulis_ or _atolocatl_, and as
_lusus aquarum_, _piscis ludicrus_, or _axolotl_, which latter name has
remained in use, in Mexico and elsewhere, to the present day. But for its
large size--it grows to a length of eleven inches--it is a nearly exact
image of the British newt larvae. It has the same moderately long, plump
body, with a low dorsal crest, the continuation of the membrane bordering
the strongly compressed tail; a large thick head with small eyes without
lids and with a large pendent upper lip; two pairs of well-developed limbs,
with free digits; and above all, as the most characteristic feature, three
large appendages on each side of the back of the head, fringed with
filaments which, in their fullest development, remind one of black ostrich
feathers. These are the external gills, through which the animal breathes
the oxygen dissolved in the water. The jaws are provided with small teeth
in several rows, and there is an elongate patch of further teeth on each
side of the front of the palate (inserted on the vomerine and palatine
bones). The colour is blackish, or of a dark olive-grey or brownish grey
with round black spots or dots.

The genus _Amblystoma_ was established by J. J. Tschudi in 1838 for various
salamanders from North America, which had previously been described as
_Lacerta_ or _Salamandra_, and which, so far as general appearance is
concerned, differ little from the European salamanders. The body is smooth
and shiny, with vertical grooves on the sides, the tail is but feebly
compressed, the eye is moderately large and provided with movable lids, and
the upper lip is nearly straight. But the dentition of the palate is very
different; the small teeth, which are in a single row, as in the jaws, form
a long transverse, continuous or interrupted series behind the inner nares
or choanae. The animal leaves the water after completing its metamorphosis,
the last stage of which is marked by the loss of the gills. One of the
largest and most widely distributed species of this genus, which includes
about twenty, is the _Amblystoma tigrinum_, an inhabitant of both the east
and west of the United States and of a considerable part of the cooler
parts of Mexico. It varies much in colour, but it may be described as
usually brown or blackish, with more