iBT. 11 NORTH AMERICAN TADPOLES — WRIGHT 23 



BUFO AMERICANUS Holbrook 



Plate 6, figure 12 



Color description from life (not Ridgway) .—The ground color is a 

 very dark brown or black overlaid with many fine gold and silvery 

 spots, these aggregated in a few places. The venter is like the back, 

 but the aggregate of bright spots are more silvery and more or less 

 iridiscent (coppery). The muscular portion of the tail is dark, like 

 the back, with a few gold-spotted areas. The crests are cloudy 

 transparent. 



General appearance. — Body small (27 mm.), ovoid, broader nearer 

 vent than eyes. Dorsal aspect shows body decidedly tapers ahead 

 of eyes. Dorsal crest low, extends but slightly on to the body to a 

 vertical just ahead of the buds of the hind legs. Dorsal and ventral 

 crests about equal to depth of the musculature. Tail short, tip 

 rounded. Spiracle sinistral, directed mainly backward but slightly 

 upward, considerably below the lateral axis. Eye above the lateral 

 axis. Eye quite dorsal, more or less closely together slightly nearer 

 lateral outline, but almost equidistant between lateral outline and 

 mid-dorsal line. Anus median, opening on a level lower than the 

 lower edge of the ventral crest. 



Mouth parts. — Teeth |^. Upper labium fringed with a continuous 

 row of labial teeth, the papillae extending onh^ to each end of this 

 fringe. The end of the second upper row does not usually extend 

 beyond the end of the upper fringe. The median space between these 

 two lateral parts of the second row is contained in either lateral row 

 of teeth 1.15-2 times normally (1.0 or 3-4 times). The horny beak 

 is contained about 1.2-1.4 in upper fringe or almost as long as first 

 or second lower labial row of teeth. First and second lower labial 

 rows of teeth equal and about 1.1 to 1.2 times longer than horny 

 beak. Third row of lower labial teeth is contained about 1.3-1.5 

 times in the first or second lower labial row. Papillary border of 

 weak papillae (as compared with B. terrestris). Lower loop of papillae 

 not pronounced as in B. terrestris. One row of papillae from upper 

 fringe to lower third labial row except for a few scattering papillae. 



Measurements. — Length of body (7.0-10.2 mm.) in tail (11.1-17.6 

 mm.) 1.3-1.7, average 1.49. Width (4.2-7.4 mm.) of body in its 

 own length 1.25-1.7, average 1.52. Depth (3.2-5.6 mm.) of body 

 1.26-1.56 in body width (4.8-7.4 mm.), average 1.35. Depth 

 2.4-5.0 mm.) of tail in length of tail 1.25-2.7, average 1.97. Muscular 

 part (1.4-2.6 mm.) 1.26-2.66 in depth of tail, average 2.04. Spiracle 

 1.3-1.8 nearer base of hind legs or vent region (2.8-5.4 mm.) than the 

 tip of the snout (4.4-7.4 mm.), average 1.54. Spiracle 1.04-1.54 

 nearer eye (2.0-4.0 mm.) than base of hind legs or vent (2.8-5.4 



