VII. Bescription of' n new Species of Agamn, brought j r o m the Columbia River by Mr. 1)oirglnss. Bjj Thomas Bell, E q . , P.R.Y. cf L.S.

Recid June 17, 1828.

Genus. A G A RI A. Dolidin.

AC A A I A DOUG L A S S I I .

'rAI3. x. A. Poris femoralibus utrinque xx.

IIabitcit in or8 occidentali Americce Borealis ad ripas fluminis Columbiae.

I x its general form, colours, and marking, this species very much resembles A . superciliosa, A . orbicuZaris, and others of the same section of the genus. The head is obtusely triangular, with i~ distinct ridge overhanging the orbits: the body sub- orbicular and depressed ; the tail tumid at its origin, from whence it becomes rather suddenly contracted, and tapers to its extremity. The head, body, limbs and tail, are covered on the upper side with small raised scales, interspersed with larger ones which are aculeated, and most of them quadran- b d a r . These form distinct ridges over the eyes, ahove the ears, across the occiput, and along the sides of the body and tail. The under side is wholly covered with small uniform smooth scales. The gular fold is of considerable size. The colour of the upper part is a mixture of yellowish-white and

VOL. X'VI. P piceous

106 3Ir. B E L L 011 (I new Species of Aganin.

piceous disposed in dots, exactly resembling mosaic work, and wit11 tlistirict, large, irregular ocelli of the latter colour, margined with white, disposed in transverse series across the back. 'l'liere is also a white longitudinal central line from the occiput to the end of tile tail. 'l'he under side is of an uniform faint white colou~*, and the fenioral pores of a sulphur-yellow.

'l'liis beautiful and highly interesting species w a s found by Rlr . David Douglass in the course of his late indefatigable and productive researches in the western parts of North America, to wliorii I am also indebted for the following account of its habits.

I t is seen in great nunihers in all woodless sandy arid deserts in the interior of the country, on the southern parts of Columbia river. On the banks of streams, in thickets composed of I'm-shia trideutcitci, d r t e ) n i s i n and Sciloin, it mas observed hy XIr. Doug- lass to take up its abode, in the holes made by species of Lcpcis, Arc to?nys , &c., wliich are alternately occupied by them and several species of Coluber, wliich resort there for the purpose of preying on these AgcrmQ and on the Marmots. I t feeds on both animal and vegetable substances. In the stomach were found coleo- pterous insects, and the leaves of I'wshio, Arte7iiisic1, and Sulvia. Like most others of the tribe it is very nimble during the sum- mer nionths, and it is then difficult to capture it ; but in April, when it first niakes its appearance, or in October, before it retires to its winter habitation, being at both seasons weakly, it may be readily taken. At such seasons the traveller is con- stantly annoyed by them during the night, seeking shelter from the cold under his blanket, and is frequently under the necessity of removing these little intruders on his rest. " In April," continua Mr. Douglass, '' I have observed the young, not exceeding half an inch in length, perfectly formed, of the same colour and equally nimble with the older ones. 'l'he co-

lour