6 TJ. S. NATIONAL MUSEUM BULLETIN 206 



adprcssed, heel reaches to posterior corner of eye; when limbs are 

 laid along the body, knee and elbow are mdely separated; when liind 

 legs are bent at right angles to body, heels just touch. Skin smooth 

 or minutely glandular excepting over the bony dorsal shields, where 

 it is pitted and rough like the bone with which it is ossified; venter 

 smooth, with some very minute glandular pits on the belly and throat, 

 especially prominent on the chin. (No external vocal sac apparent 

 in the male.) 



Dimensions. — Head and body 19 mm.; head length 7 mm., width 

 7.5 mm.; femur 7.5 mm.; tibia 7.5 mm.; foot 5 mm.; hand 4 mm. 



Mathematical analysis (in percentage of the total length) : 



Color in alcohol. — Dorsum and venter uniform pale buff, immaculate. 

 Eyes black and beadlike, the pigment showing distinctly through the 

 thin upper eyelid. 



Color in life. — The adult frog from Tijuca, city of Rio de Janeiro, 

 was brilliant, immaculate cadmium orange above, chrome yellow 

 below. The eye was beady jet black. The bonelilfe saddle on the 

 back was different in texture from the surrounding skin, but similar 

 in color. 



Remarks. — This individual and five others from Corcovado, also 

 within the city limits, were examined and compared with nine exam- 

 ples from Petropolis to find out the effect of age on the development 

 of the bony saddle. Irrespective of their locality, all the adults, 

 measuring 17 to 20 mm. in total length, had the bony plate very 

 strongly developed, although the shape and size of these plates were 

 subject to a good deal of individual variation. The gross form of the 

 bony deposition appears to be typically that of a thickened hourglass 

 across the back, with one or several additional vertebral bony "islands" 

 anterior and posterior to the "stem" of the hourglass, while in a few 

 instances these "islands" have completely fused with the main part 

 of the plate so that it is almost a parallelogram. The head is com- 

 pletely covered with bone except for a Httle round area behind each 

 upper eyelid. , The knobs of bone over the parotoid region are particu- 

 larly prominent and extend backward beyond the occipital ossifica- 

 tion. In the eight younger specimens, measm-ing from 16 down to 13 



