The Swamp Tree Frog 



THE SWAMP TREE FROG 1 

 Cborophilus nigritus Le Conte. 



IDENTIFICATION CHARACTERISTICS 



Colour; Changeable from a colour so dark that it is nearly 

 black, to flesh colour. When light, the colouration may be bluish 

 or ash grey, fawn colour, or even salmon or red in tone. Iris 

 golden or copper-coloured. There is a dark stripe, which begins 

 at the muzzle and extends through the eye and ear, and less 1 con- 

 spicuously to the middle of the side of the body or beyond. This 

 dark colour is bordered below by a light band which extends 

 to a point back of the arm. The immediate edge of the jaw is 

 dark. There may be a pattern of dark lines or spots on the back, 

 head, and legs. This pattern consists typically of the following: 

 i. Three longitudinal stripes (or series of spots). The middle 

 one of the three occupies the midline of the back and may fork 

 posteriorly. The two others extend backward parallel to this, 

 from the posterior angles of the eyes. 2. A transverse band 

 between the eyes .connected with the median stripe. 3. Cross- 

 bands, or more or! less irregular lines of spots, on the hind legs. 

 The underparts are yellowish white. The throat of the male is 

 greenish yellow. (See Studies of Chorophilus, Fig. 185.) 



Measurements: Size small, i.e. length I inch, slightly more 

 or less. Body relatively long and slender. Length of head 

 variable. The greatest length is presented by the Western and 



1 Chorophilus nigritus Le Conte, Chorophilus Jeriarum Baird, Chorophilus triseriattts Wied, 

 Cope, Batrachia of North America. 



The Chorophilus material is confusing, and insufficient to settle any problems. Chorophilus 

 nigritus, jeriarum, and Iriseriatus were described originally as distinct species. O. P. Hay, in 1892, 

 called all three one species, making the latter two subspecies of the nigritus form (see quotation fol- 

 lowing). Dr. Stejneger of the National Museum has identified a subspecies seplentrionalis well repre- 

 sented by forms from the extreme North. I have allowed jeriarum, triseriatus, and septcntrionalis 

 to stand as subspecies of nigritus. However, the whole subject is in need of investigation and is open 

 to revision. 



" Snout acuminate, width of head in length of head and body 2.8 to 3 times; heel reaching 

 in front of orbit; size larger; colour leaden to fawn, with three rows of dark spots above, these some- 

 times united in continuous bands. South Carolina to Mississippi." (Nigritus.) 



" Snout shorter; width of head in length 3-3.25 times; heel reaching to front of orbit; length 

 of body in total length of hind leg from 1.4 to 1.7; colour ash or brownish, eyelids involved in median 

 stripe, three parallel stripes above seldom interrupted. Eastern United States to Illinois. (Fcriarum.) 



" Snout drawn out; width of head in length 3.5 to 3.6 times; heel reaching only to tympanic 

 disk; length of body in total length of hind leg 1.24 to 1.5 times; colour ash to brown, with three par- 

 allel dark stripes, median often forked behind, spot on each eyelid. New Jersey to New Mexico and 

 Idaho." (Triseriatus) O. P. Hay. 1892. 



