254 ZOOLOGY. 
the latter with compressed tail and aquatic. The necessity of further 
sub-division has, however, become fully apparent, and the old distinction 
into land and water salamanders no longer tenable as parallel to any 
anatomical features. Thus, of the highly natural genus Votophthalmus, one 
species is the most aquatic of all American forms, and the other the most 
terrestrial; yet the two are so much alike in shape as to render it a matter 
of some difficulty to distinguish them. Without attempting any systematic 
arrangement of the genera of salamanders we shall take them up in 
geographical order, beginning with those of North America. 
The genus Ambystoma embraces the greatest number of species and 
those of largest size. Its characteristics are, the entire absence of teeth on 
the sphenoid bone, the nearly transverse undulating line of vomerine teeth, 
in a measure forming the chord of the are constituted by the outline of 
the upper jaw. The tongue is broad and fleshy, and entirely adherent 
except at the very edge. The species are mostly stout and clumsy, some 
of them, as A. punctata, A. opaca, and A. jeffersoniana, terrestrial in their 
habits, with rounded tail and cylindrical toes ; others again sub-aquatic, 
with a much compressed tail, and short, broad, flattened toes. The genus 
is found throughout the United States, and across to the Pacific ocean, 
peculiar species occurring in California, Oregon, and New Mexico. . The 
terrestrial species exude a copious, milky, viscid excretion, from all parts 
of the body. The development of the larva of the best known species has 
already been referred to. The lungs have a higher degree of organization 
than in the other genera, being subdivided into cells of moderate size. 
The next genus is Votophthalmus, known by the ocellated spot on the 
back in all but one species, the small rudimentary tongue, the absence of 
teeth on the sphenoid bone, the arrangement of the vomerine teeth in an 
acute V, as in the true Tritons, the densely granulose skin, the three 
foramina in the side of the neck, &c. The best known species are, JN. 
viridescens (Triton dorsalis) and N. miniatus (Triton symmetrica). The 
former species is exceedingly abundant throughout the United States, and 
is entirely aquatic. It has even been kept for more than a year im a glass 
jar filled with water, coming up to the surface from time to time to take in 
a mouthful of air. In the spring of the year a broad fin becomes developed 
along the back and tail of the male, and the feet enlarge with the addition 
of a black cartilaginous mass on the toes and inside of the thighs, for the 
purpose of enabling it to hold on to the female. This is done by clasping 
her round the throat with the hind legs, and retaining the hold for some 
hours, or longer, jerking her round in the water most unmercifully during 
the whole time. A quantity of seminal matter is finally discharged, which, 
becoming diffused in the water, fecundates the ova while still in the lower 
part of the oviduct. The eggs are laid singly, of an ellipsoidal shape, and 
invested by a very glutinous coat, by which it is attached to the middle of 
an immersed leaf, which is then doubled over it by the exertions of the 
female. The eggs, after remaining for some time in this way, finally give 
birth to small larve, the general character of whose metamorphoses is 
much the same with that of the species already described. The male 
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