ART. 11 NORTH AMERICAN TADPOLES — WRIGHT 17 



Mouth parts. — Teeth f, f, ^, f . Whole labium (upper and lower) 

 with continuous row of papillae except on the upper labium where a 

 pronounced median interval is toothed. This median row is about 

 equal to the first lower labial row of either side. From upper labial 

 interval of teeth downward either side and across the lower labial 

 border there is at least one row of inner papillae. Opposite the ends 

 of the horny beaks are several rows of them filling in the space be- 

 tween upper and lower labia. The next series of teeth (the second) 

 below the upper toothed interval is usually not continuous rarely 

 continuous. Usually one median end slightly overlaps the end of its 

 counterpart of the other side. The third series has a short median 

 interval one-half the distance of the upper toothed interval or first 

 series or slightly more than a similar interval in the third lower labial 

 series. Either half of the upper third series is slightly less in length 

 than the horny beak and about equal to either half of the lower third 

 series. Either half of the fourth series is longer than a similar half 

 of the first lower labial series or shorter than that of the second series. 

 The interval of this fourth row is about two-thirds the length of the 

 horny beak or contained one and one-third to one and one-half times 

 in the interval of the first lower labial series. The fifth series is a 

 short lateral row about equal to the lateral row of second lower labial 

 series. Beneath the fifth series and very closely placed to it is a 

 short row almost opposite the end of the horny beaks. On the 

 lower labium are five series, the first three not continuous, the last 

 two continuous. The median interval of the first lower labial series 

 is about equal to the horny beak in length. The interval of the 

 second series is usually about equal to or less than the interval of 

 fourth upper series. The interval of the third lower series is very 

 short indeed, shorter possibly than the interval of the third upper 

 series. The fourth continuous lower row is 1.6-1.7 times the horny 

 beak in length. The fifth continuous lower row is 1.4-1.5 times in 

 he fourth continuous lower row. 



Measuremenis. — Length of body (10-12.2 mm.) in tail (12.8-17.6 

 mm.) 1.1-1.7, average 1.34. Width (6.0-7.4 mm.) of body in its own 

 length 1.4-1.8, average 1.64. Depth (4.0-6.8 mm.) of body 1.03-1.50 

 in body width, average 1.23. Depth of body 1.73-2.5 in body 

 length, average 2.04. Depth (3.4-5.4 mm.) of tail in length of tail 

 2.5-4.0, average 3.14. Muscular part (2.0-3.0 mm.) 1.45-2.5 in 

 depth of tail, average 1.98. Spiracle 1.24-1.66 nearer base of hind 

 legs or vent region (4.4-6.0 mm.) than the tip of the snout (7.0-8.0 

 mm.), average 1.41. Spiracle equidistant between eye (1.44-5.8 mm.) 

 and base of hind legs or vent (14.4-6. mm.), average 1.0. Eye 1.4- 

 1.8 nearer to tip of snout (3.0-3.6 mm.) than to spiracle (4.4-5.8 mm.) 

 average, 1.52. Nostril 1.5-2.25 nearer eye (1.0-1.8 mm.) than snout 

 6359—29 2 



