Rana sphenocephala 431 



erous crypts more or less distinct in mature tadpoles and sometimes quite 

 distinct in half grown tadpoles. The dorsal row of either side starting near 

 the dorsal crest goes diagonally forward and outward to join the principal 

 lateral row which goes from above the middle of the insertion of the tail 

 musculature to back of the eye where a supraorbital and an infraorbital branch 

 goes forward. 



Mouth parts: Teeth 2/3 or 3/3. Upper labium edged by a fringe of 

 teeth, the fringe longer than the beak. Below either end of this fringe is a 

 long row of teeth about 2/3-1/3 the length of the upper fringe. The median 

 space one half to one times the length of the lateral row. Usually it is less 

 than once the lateral row while in R. pipiens it is almost invariably more than 

 once the lateral row. In many tadpoles as they approach transformation 

 there appear in either corner a short third row of labial teeth on both sides 

 or sometimes on one side only. Also in mature tadpoles it not infrequently 

 appears. For example, in 19 12 we secured 23 tadpoles of this species, of 

 which six had the third row on either side, this row .33-.24 the length of the 

 second row and in three specimens the third row was present in only one side. 

 On the lower labium are three rows of teeth. The third row is shorter than 

 the single row of labial papillae, 1/3 to 2/7 shorter than the second or first 

 row, or about 1/6 to 1/5 shorter than the horny beak. First and second 

 lower labial rows about equal and slightly longer than beak. First one is 

 sometimes subdivided in the middle. 



Measurements. Length of body (19.0-25.0) in tail (28.5-37.5 mm.) 

 1. 35-1. 66, average 1.53. Width (10.-16.5 mm.) of body in its own length 

 1. 56-2. 1, average 1.77. Depth (9.0-15.0 mm.) of body .8-1.36 in body 

 width, average i.i. Depth of body 1.5-2.3 in body length, average 1.95. 

 Depth (10. 5-16. 5 mm.) of tail in length of tail 2.0-2.66, average 2.65. Mus- 

 cular part (6.0-9.5 mm.) 1.35-2.35 in depth of tail, average 1.80. Spiracle 

 1. 2-1. 7 nearer base of hind legs or vent region (8.0-14.0 mm.) than the tip 

 of the snout (12. 5-16.0 mm.), average 1.46. Spiracle 1.1-1.86 nearer eye 

 (5.0-9.0 mm.) than base of hind legs or vent, average 1.46. Eye i.i 5-1.3 

 nearer to tip of snout (5.0-7.0 mm.) than to spiracle (5.0-9.0 mm.), average 

 1.2. Nostril to snout equal to nostril to both 3.6-5.0 mm. Mouth (3.0-5.0 

 mm.) usually 9-1.6 larger than internasal space (2.2-5.0 mm.), average 1.25. 

 Mouth contained 1.4-2.0 (average 1.68) in interorbital distance (5.5-7.5 mm.) 

 Internasal space contained in interorbital space 1.4-2.3, average 1.95. 

 The measurements of the largest tadpole are : 



mm. mm. 



Spiracle to vent 14.0 



Spiracle to eye 7 . 5 



Eye to snout 6 . 5 



Eye to nostril 4 . 5 



Nostril to snout 3 . 5 



Mouth 4 . 5 



Interorbital distance 7.0 

 Internasal distance 5 . o 



