Hylidse 



Measurements: Size large for a tree frog, i. e. length 2| inches 

 or more. Head short compared with total length (| inches in 

 frog of 2| inches.) Leg measurement to heel equals length of 

 body forward to the eye (female). 



Structure: Skin of upper parts relatively smooth, set every- 

 where with very fine tubercles. Underparts granulated, even on 

 throat. (Fig. 183.) Eyes widely separated. Canthus rostralis 

 unusually prominent, nostrils near their terminal point. Ear 

 round, nearly as large as the eye. (Fig. 182.) Distinct fold of 

 skin over the ear from eye to shoulder. A prominent fold across 

 the breast. Disks of fingers and toes large. Webs of toes me- 

 dium in size. Fingers slightly webbed. (Fig. 181.) Inner sole 

 tubercle small; outer lacking. Tubercles under joints of fingers 

 and toes fairly prominent. (Fig. 183.) A conspicuous tarsal 

 fold. 



Range: Smilisca haudinii is typical of Mexico and Central 

 America. In Texas, it has been reported from Brownsville and 

 Helotes. 



This tree frog is one of the largest found in North America. 

 It bears a superficial resemblance to Hyla versicolor, the Common 

 Tree Frog, (see Figs. 134 to 142), but can always be recognized by 

 definite characteristics, as follows: The head is more deeply angled 

 along the line of the canthus rostralis. The body is relatively 

 longer, the head narrower; the skin is less tubercular. The ear 

 is much larger. The black patch on the shoulder and the white 

 one encircling the arm at its insertion are peculiar to this species, 

 while, on the other hand, this frog lacks the reticulations on the 

 posterior surface of the femur characteristic of Hyla versicolor. 



Smilisca haudinii is like Hyla versicolor, also, in its sluggish 

 tendencies. When it is aroused, it is a powerful leaper. 



Its colour changes are no less remarkable than is usual among 

 the members of the Hylidae. It may change rapidly from a dark 

 unspotted condition to a light unspotted condition, through me- 

 dium shades displaying a conspicuous colour pattern. (Figs. 178 

 to 180.) For instance, we remove it from its hiding-place under 

 moss and leaves, and find it nearly black. Put it in bright light 

 and watch. Slowly the colour becomes less dusky and the pattern 

 begins to appear. It is most conspicuous in its outlines, which 



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