_Caput breve, latum, subtriangulare. Aures parvæ, ovatæ, margine lævi.
Nares magnæ, rotundæ. Collum infrà transversè, ad latera
longitudinalitèr plicatum. Corpus subdepressum, non cristatum. Cauda
teres, breviuscula, læevis. Pedes breves, robusti. Squamæ capitis
numerosæ, parvæ, rotundatæ, non imbricatæ—corporis atque caudæ suprà
minimæ, læves, convexæ, paulò imbricatæ, infrà læves, planæ. Pori
femorales et præ-anales in utroque sexu nulli. Dentes palatini
nulli._
The new genus which I have thus defined, resembles very closely, in most
of its characters, the genus _Leiosaurus_ of Bibron; from which, indeed,
it scarcely differs, excepting in the absence of palatine teeth, and in
the form of the suborbitar plates, which in _Leiosaurus_ are all
distinct, and of nearly equal size; whereas, in the present genus, three
of these are united to form one plate, resembling that in
_Proctotretus_, and some other _Agamidæ_. In other respects the genera
are very closely allied; but the existence or non-existence of palatine
teeth, is a character of so much importance, that it appeared to me,—and
in this opinion I am supported by M. Bibron, who examined the specimens
with me,—that they should be considered as distinct. Both the genera are
natives of South America. Of _Leiosaurus Bellii_ (Bibr.) the only known
specimens were presented to me by Capt. King, who obtained them during
his survey, from whom also I obtained specimens of one of the species of
the present genus, _D. Bibronii_.