ART. II NORTH AMERICAN TADPOLES — WRIGHT 59 



flecks over tail except near the edges of the tail crests. In the younger 

 tadpoles without blackish spots the black is in specks all over the 

 tail and these faintly appear on the tail crests as dark edges. 



Iris light cadmium to buffy yellow with dusky in front and behind 

 ■ the pupil. 



General appearance. — Tadpole medium (40 mm.), full, and deep 

 bodied. Tail acuminate; tip acuminate, sometimes acute. Tail 

 long. The dorsal and ventral crests about equal and about equal to 

 musculature in depth. The dorsal crest extending on to the body to 

 the vertical about midway between the eye and spiracle. Spiracle 

 sinistral, directed upward and backward, far below lateral axis, the 

 spiracular opening very visible as a round or elliptical opening. 

 Eye on lateral axis, in dorsal aspect on the lateral outline and in 

 consequence visible from the venter. Anus dextral, at or only 

 slightly above the lower edge of the ventral crest. Muciferous 

 crypts not distinct. As they approach transformation the whole 

 tail becomes spotted with conspicuously dark and light spots. 



Mouth parts. — Teeth f. Upper labium fringed with a continuous 

 row of labial teeth ; the papillae extend above and inward beyond the 

 end of the fringe for about one-fourth to two-ninths of the length of 

 the upper fringe. The end of the second row is usually even with the 

 end of the upper fringe. The horny beak is contained in the upper 

 fringe 2-2.3. Median space between the lateral second upper labial 

 row three or four times in the length of the lateral row. The latter 

 row about two and one-half times in the upper fringe. Inner papillae 

 extend beneath the third lower labial row of teeth after giving a two- 

 rowed appearance below it, like H. andersonii, H.femoralis, H. versicolor 

 or H. sguirella. The third lower row of teeth, however, is not like this 

 group, but shorter, like H. gratiosa or H. crucifer. In one specimen 

 it was absent, with the papillae below also absent. This third row 

 is contained two-fifths to one-fourth in the length of the first or 

 second row of lower labial teeth. The first and second rows (lower 

 labial) about equal or one and one-third greater in length than horny 

 beaks. Sometimes fringes are united by their ends as in H. gratiosa. 



Measurements. — Length of body (11-15 mm.) in tail (16-25 mm.) 

 1.25-2.0, average 1.6. Width (6-7.5 mm.) of body in its own length 

 1.8-2.2, average 1.9. Depth of body (6.0-7.0 mm.) equals body 

 width. Depth of body 1.69-2.5 in body length, average 1.95. 

 Depth (7.0-8.0 mm.) of tail in length of tail 2.0-3.125, average 2.75. 

 Muscular part (4.0 mm.) 1.75-2.4 in depth of tail, average 1.925. 

 Spiracle 1.15-1.6 nearer base of hind legs or vent region (5.0-7.0 mm.) 

 than the tip of the snout (8.0-9.0 mm.), average 1.375. Spiracle 

 1.4-2.3 nearer eye (3.0-3.5 mm.) than base of hind legs or vent, 

 average 1.88. Eye 1.1-1.66 nearer spiracle (3.0-3.5 mm.) than to 



