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Show 22 ZOOLOGY OF THE VOYAGE OF THE BEAGLE. of the former species in general form and arrangement, excepting that they are smaller and less elevated. Those beneath the anterior part of the lower jaw are much smaller; but the rest on the under parts are similar to the former. The head is of a dull light-brown colour, with a few obscure darker spots. The general ground colour of the back is " bluish gray, tinged with rust colour;" there arc five transverse bands across the back, which are composed principally of numerous, close, small, dark. brown spots, on a bluish-gray ground, darker than the intervals, and without any red tinge; and each band is marked on the posterior margin with strongly defined semilunar indentations, bordered with yellowish-white, or bright yellow. These bands are continued on the tail, where they become half-rings. DIMENSIONS. Length of the head .................... . of the body .... . .............. . of tho tail ..................... .. Total length ... Length of anterior extremity .. . ..... . of posterior extremity ........ . Inches. Lines. 1 2 2 8 5 7 1 2 6 4 1 GENus-AMBLYRYNCHUS. Bell. AMBLYRYNCHUS DEMARLII. Bib1·. PLATE XII. Crista supm cervicem elevatim·e, supm dorsum lt?tmiliore ; tuberculis verticalibus subdepressis, occipitalibus conicis; cauda tereti. Amblyrynchus Demarlii. Bibr. Ilist. Rept. IV. p. 107. This species was first described by Mons. Bibron in the "Histoire des Reptiles," and so fully as not to require any detailed account of its characters here. It has not, however, hitherto been figured, and it is thought very desirable to embrace so good an opportunity of giving a representation of so interesting an animal. Its most important structural peculiarities will be alluded to in the account of the next species, which is an aquatic form, whilst the present is strictly terrestrial. The toes are long, compared with those of the other, and so unequal as to constitute essentially an ambulatory form. By Mr. Darwin's observations we are now enabled fully to confirm Mons. Bibron's suggestion, that this species was from the Galapagos, and to establish the genus as strictly appertaining to that curious and interesting locality. |