28 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 74 



eye where the supraorbital branch goes over eye and above nostril 

 on to snout above the mouth. This same lateral branch sends off 

 an infraorbital branch which in front of the eye swings far downward 

 away from the nostril and ends near the comer of the tadpole mouth. 

 Just back of the eye the infraorbital branch sends a loop upward 

 and then abruptly downward to the venter where it goes forward 

 as a mandibular branch to the mouth. Another lateral series low 

 on the body runs evenly forward until it loops over the spiracle. 



Mouth parts. — Teeth ■^. The teeth are after the R. sylvatica type. 

 Occasionally in some of the young forms it may be two-four or rarely 

 two-three. The upper labium is fringed with a row of teeth much 

 larger than the beak (about one and one-half times the beak). The 

 second row of lateral teeth is of medium length, is about one-fourth to 

 two-ninths of the length of the upper fringe. The median space between 

 this second row of upper labial teeth is one to two and three-tenths 

 times the length of either lateral row. The third upper labial row is 

 about one-half of the length of the upper fringe. The lower labium has 

 four rows of teeth, the first two about equal and sometimes the third 

 also equal to the other two or shghtly shorter. The first row often 

 subdivided and sometimes the second row\ The fourth row is equal to 

 the single row of lower labial papillae, is one-third or one-half to 

 four-ninths the length of the first lower row. Inner papillae on side 

 of labium extend to the end of the fourth lower labial row of teeth. 



Measurements oj average tadpole. — Length of bodj^ (16-23.5 mm.) 

 m tail (6.0-11.0 mm.) 1.36-2.05, average 1.60. Width (9.5-15.0 mm.) 

 of body in its own length 1.45 1.85, average 1.63. Depth (7.0-11.0 

 mm.) of body 1.1-1.8 in body width, average 1.43. Depth of body 

 2.0-3.0 in body length, average 2.325. Depth (6.0-11.0) of tail in 

 length of tail 2.5-5.7, average 3.93. Muscular part (3.5-6.0 mm.) 

 1.33-3.0 in depth of tail, average 2.0. Spiracle 1.0-1.33 nearer base 

 of hind legs or vent region (9.0-12.0 mm.) than the tip of the snout 

 (9.5-14.0 mm.), average 1.17. Spiracle 1.45-2.375 nearer eye (4.0- 

 8.0 mm.) than base of hind legs or vent (5.8-12.0 mm.), average 2.05. 

 Eye 1.875-1.33 nearer to tip of snout (30-6.0 mm.) than to spiracle 

 (4.0-8.0 mm.), average 1.11. Nostril 1.0-1.75 nearer eye (2.0- 

 3.0 mm.) than snout (3.0-4.0 mm..), average 1.32. Mouth (3.0-4.0 

 mm.) usually 1.08-1.75 larger than internasal space (2.0-3.5 mm.), 

 average 1.33. Mouth contained 1.0-1.7 (average 1.17) in interorbital 

 distance (3.0-6.0 mm.). Internasal space contained in interorbital 

 space 1.3-2.0, average 1.53. 



