A New Treefrog from the Disfn'ri of Columbia. 77 



Color variation in Hyla criilala is very great, and as in other treefrogs 

 chiefly dependent on the character of tlie surface on which the animal is 

 resting. When searching for food among the leaves and stems of pickerel 

 weed and pond- lilies, Hyla evittata assumes a yellowish grass-green tint, 

 closely harmonizing with the color of the plants. In captivity the color 

 is usually darker and duller, this tendency culminating in rich myrtle- 

 green and dark olivaceous brown in individuals that have rested on brown 

 bark or have remained long hidden in a dark corner. The color during 

 hibernation under moss and sod is much paler than that assumed by the 

 same individuals when hiding in similar places during the summer. 

 However great the changes in color may be, at no time is there developed 

 any trace of stripes. If rudiments of these are present they are always 

 visible. Similarly in Hyla cinerea, which undergoes an exactly parallel 

 series of color changes, the stripes are never affected in distinctness, 

 though they are most conspicuous when the general color of the animal 

 offers the greatest contrast. The stripes of Hyla cinerea vary in living in 

 dividuals from silvery white to metallic reddish gold. The body stripes 

 are almost invariably bordered by a narrow black line. When the animal 

 is in repose the body stripes are about 1.5 mm. in width, but when it is ut 

 tering its note the body becomes greatly swollen and the stripes broaden 

 to three times their normal width, and at the same time assume their 

 brightest colors. The leg stripes are narrower and less sharply defined 

 than the body stripes, and their dark margins are less constant in devel 

 opment. 



As to the constancy of the color differences between the two forms : I 

 have handled about two dozen living and freshly killed specimens of 

 Hi/la evittata, and have probably seen nearly as many more at a distance 

 of only a few feet. Among these one had a faintly developed stripe at 

 the angle of the jaw. Of the twenty-two alcoholic specimens collected 

 by Mr. Hay and now in the National Museum, eight have traces of the 

 body stripe, which, however, in no instance is margined with black, or 

 as sharply defined as in those southern specimens in which the stripe is 

 shortened and narrowed. Of sixty-one specimens of Hyla cinerea (seven 

 received alive from H. H. & C. 8. Brimley,* the others preserved in alco 

 hol in the U. S. National Museum f) there is considerable variation in 

 the leg stripes, but with only t\vo exceptions the body stripe, though 

 varying in length and breadth, is conspicuously developed, definite in 

 outline, and usually margined with black. In the two abnormal indi 

 viduals (one from Bay St. Louis, Miss., the other from New Orleans, La.) 

 the leg stripes are absent, and the body stripes reduced to mere traces 

 near the angle of the jaw. When forwarding the unstriped specimen 

 from Mississippi, the Messrs. Brimley wrote that it was the only one of 

 the kind observed among the large number that have passed through 



* Taken at Bay St. Louis, Miss. 



t From the following localities : Texas, New Braunfels ; Louisiana, New r 

 Orleans; Florida, Clear Water, Georgiana, Indian River, Lemon City, 

 Marco Island, Pensacola; North Carolina, Beaufort. 



