Reptiles and Aniphib/'aus of Illinois. 331 



Family ENGYSTOMID^. 



No parotids. Tympaaum concealed. Fingers and toes 

 not expanded at their tips, the former without, the latter with 

 or without, webs. No teeth. Hearing apparatus fully devel- 

 oped. Prefrontals fully developed, in contact with each other, 

 and with the parieto-frontals. No overlapping sternal carti- 

 lages. Clavicles and precoracoids sometimes wanting. Trans- 

 verse processes of sacrum dilated. 



This is a small but widely distributed family containing 

 eight genera and about twenty-one species. It is represented 

 in North America by the single genus Engystoma. 



ENGYSTOMA, FiTZmGER. 



Fitzinger, Neue Klassiflcatioa der Reptilien, 1826. 

 Dum. et Bibr., Erp. Gen. 1841, IX., p. 738. 



De Kay, Nat. Hist. N. Y., I., Zool. III., 1842, Kept, and Amph., 

 p. 65. 



Head small, pointed, continuous with the body; mouth-cleft 

 small; tongue free behind, elliptical, entire. Limbs stout and 

 rather short. Eustachian ossicle very small. Males with an 

 internal, sub-gular vocal sac. 



The genus contains twelve species, most of which occur in 

 tropical America. 



Engystoma carolinense, Holbr. Nebulous Toad. 



Engystoma carolinense, Holbr.. N. A. Herp., 1842, Vol. I., p. 83. — 

 Dam. et Bibr., Erp. Geu., 1841, VIIl., p. 743.— LeC, Proc. 

 Acad. JSfat. Sci. ThUa., 1855, VIIL, p. 430.— Gunther, Cat. 

 Batr. Sal. in Coll. Brit. Mas., 1858, p. 51.— Cope, Ctieck List 

 N. A. Batr. and Kept., 1875.— Boulenger, Cat. Batr. Sal. m 

 Coll. Brit. Mus , 2d ed., 1882, Sal. Eciudata. p. 162.— Yarrow, 

 Check List N. A. Kept, and Batr., 1882. — Davis and Rice, 

 Bull. 111. State Lab. Nat. Hist., I., No, 5, 1883, p. 18; Bull. 

 Chicago Acad. Sci., 1883. 



Body stout, oval. Skin smooth, with a distinct fold just 

 behind the head. Head depressed, flat above, triangular in 

 contour. Eye small. Lower jaw incised at the symphysis, 

 with a rounded eminence occupying the bottom of the incision. 

 Legs rather short, but stout, the femora of the hind legs being 



