ATELOPUS.—ENGYSTOMA. 209 
Coloration very variable. The ground-colour is black, the ornamental colours pink, 
yellow, and green. ‘The latter are distributed in various patterns, in the form of 
spots, or longitudinal or transverse bands, irregularly and more rarely symmetrically. 
The upper or lower parts may be black, almost uniform, or pink with scarcely a trace 
of black. In some of the most aberrant colour-variations the ground-colour is greyish, 
and the yellow bands are edged with black ; in others the colours assume a reticulated 
pattern ; and, finally, specimens occur of a brownish-olive, mottled and dotted with 
darker, the abdomen in these being yellow, with some irregular black linear figures. 
Extremely common and widely distributed in Costa Rica. 
Fam. ENGYSTOMATIDA. 
ENGYSTOMA. 
Engystoma, Fitz. N. Class. Rept. p. 65 ; Giinth. Batr. Sal. p. 51; Bouleng. Batr. Sal. p. 160. 
‘Tongue elliptic, free and entire behind; a transverse ridge of the mucosa between 
the choane. Vomerine teeth none. Tympanum hidden; ostia pharyngea narrow. 
Fingers and toes free, without disks. Outer metatarsals united. Precoracoids and 
omosternum absent; sternum cartilaginous. Skin smooth. 
1. Engystoma ustum. 
Engystoma rugosum, Giiuth. Batr. Sal. p. 52 (nec Dum. et Bibr.). 
Engystoma carolinense, part., Ginth. Batr. Sal. p. 51; Brocchi, Miss. Sc. Mex., Batr. p. 93. 
Engystoma ustum, Cope, Proc. Ac. N. Sc. Philad. 1866, p. 131; 1871, p. 216; Brocchi, Miss. Sc. 
Mex., Batr. p. 94, t. 10. fig. 1; Bouleng. Batr. Sal. p. 161. 
Systoma ustum, Cope, Journ. Ac. N. Sc. Philad. vi. p. 194 (1867). 
Engystoma mexicanum, Peters, MB. Ak. Wiss. Berlin, 1869, p. 881. 
Hab. Mexico, Presidio de Mazatlan (Forrer), Agua Delgada, Guadalajara (Buller), 
Guanajuato (Dugés), Cordova (Sallé), Vera Cruz and Tehuantepec (Sumichrast), 
Coatzocoalcos (Streets). 
Metatarsus with two tubercles. 
2. Engystoma pictiventre. 
Engystoma pictiventre, Cope, Proc. Am. Phil. Soc. 1886, p. 272. 
Hab. Nicaraaua (Bransford). 
One small metatarsal tubercle. Snout twice as long as the eye, and projecting well 
beyond the mouth. No fold across the occiput ; skin smooth. First finger shorter than 
