312 U. S. NATIONAL MUSEUM BULLETIN 206 



tinct wide white line on posterior femur bordered above and below 

 by dark brown lines, the upper part of femur, tibia, and foot with 

 four or five dark brown crossbars; a wide black stripe from tip of 

 snout through loreal region and across ear to shoulder, the lip below 

 light-bordered, this light stripe ending as a white spot in front of 

 shoulder; a short dark line from angle of lower jaw beneath this white 

 spot; a short black stripe on anterior part of upper arm, and a similar 

 one below forearm. Venter buff, immaculate except for a few small 

 dark spots around edge of mouth and on lower tibia and foot. Soles 

 of feet dark brown. 



Variations. — In spite of its extensive range, the variation in critical 

 body measurements is well within the range found in a single species. 

 The adpressed heel may reach the posterior corner of the eye, or as 

 far as the nostril. The snout is sometimes very bluntly rounded, at 

 other times somewhat more acuminate. A single pair of dorsolateral 

 folds occurs in all specimens, but below these may be one or several 

 short lateral folds, usually marked towards the groin by a row of 

 glandular tubercles. The gland at the angle of the mouth is better 

 developed in some frogs than in othei-s, often projecting appreciably 

 outwards behind the tympanum. Its distinctive color, dark brown 

 above and white below, makes it easy to observe in most preserved 

 material. The mottling of the back may be coarse, fine, or scarcely 

 apparent, or it may take the form of short longitudinal stripes. The 

 white, dark-bordered stripe on the posterior femur is always present. 



Remarks.- — This species is localized and not very common. Its 

 voice is a whistle often repeated, in pitch somewhat like that of a whip- 

 poor-will. The eggs are laid in holes in the ground from September to 

 November and many tadpoles emerge when the rain comes,. 



Cope's type of Cystignathus poecilochilus, USNM 4347, from near 

 Turbo, Colombia, though soft and flabby, is still well enough preserved 

 to allow of careful comparison with Brazilian examples of Leptodactylus 

 mystaceus. The chief difference seems to be that the type of 'poecilo- 

 chilus has a bluntly rounded snout, instead of the pointed, transversely 

 ridged snout of most Brazilian mystaceus, yet an occasional one from 

 Brazil has a rounded blunt snout, so that this character must be con- 

 sidered unstable. The interorbital width in the type is actually a little 

 less than the width of the upper eyelid, and not equal to it, as reported 

 by Boulenger (1882a, p. 243), but in all the Brazilian specimens at 

 hand, as well as one from Panamd (close to the type locality), the inter- 

 orbital diameter is less than the width of the prominent upper eyelid. 

 Dr. Dunn writes me, under date of Sept. 24, 1949, that he believes 

 poecilochilus from Panamd to be very close to mystaceus but that he 

 considers the Andes a barrier to their true specific identity. 



A flat ovoid or kidney-shaped gland considerably larger than the eye 



