General Discussion 41 



the beak and the lower labial teeth from the row nearest the beak to the outer 

 one next the papillose border." Possibly when our North American forms 

 are described Boulenger's system may prove the better but we have kept 

 to the first for consistency and other reasons. In the Scaphiopodidae some- 

 times the small upper row of teeth in labial border is lost yet the variations 

 come most frequent in the small rows at either corner of the horny mandibles. 

 In the Ranidae the greatest loss comes also in this same region near the ends 

 of the horny beak. In the Hylidae, forms like Hyla crucifer, however, often 

 lose the third outer lower row, the goatee, 

 a . Mouth disk absent ; no labial teeth ; no papillae ; no honry beaks ; spiracle 

 median near anus; nostril within edge of mouth fold; eye on a canthus; 

 tadpoles (23-26.4 mm) small; black or grayish olive tadpoles with a 



stripe on the middle of the tail musculature Brevicipitidae. 



b. Tail sometimes with black tip; eyes plainly visible from ventral 

 aspect; inner face of upper labial edge with no black pointed escres- 

 cences ; lower mandibular prolongation light ; general coloration black 

 with purplish gray or hair brown dots; venter with white or yellowish 

 bands and large blotches; sides of body with same coloration; light 

 band at base of tail musculature prominent (even in alcohol). Egg 

 with truncate outer envelope, giving mass a mosaic appearance on 

 water's surface. Virginia — Florida — Texas, and up Mississippi 



River to Indiana Gastrophryne carolinensis. 



aa . Mouth disk present ; upper and lower labial teeth ; labial papillae ; horny 

 beaks present; nostril free of mouth; eyes dorsal close together; tail tip 

 rounded. 



b. Spiracle sinistral; upper labial teeth not with two close rows on each 

 ridge; labial teeth 1/3, 2/2, 2/3, 2/4, 3/3, 3/4, 4/4 to 6/5; upper and 

 lower horny beaks, papillae on lower edge of labium absent or one 

 or two rows: 

 c. Anus median; spiracle lateral below the lateral axis (of tail mus- 

 culature projected forward) sometimes as much ventral as lateral; 

 upper tail crest extends on to the body to a vertical nearer hind 

 legs than the spiracle or only half way; viscera visible (in pre- 

 served specimens) through the skin of the belly, 

 d. Labial teeth 3/4 to 6/6; papillae extending completely 

 around the border of the labium except for a short toothed 

 median interval above (sometimes absent in one species); 

 papillary border not emarginate on each side; eyes nearer 

 mid-dorsal line than lateral outline, on lateral axis; tadpoles 

 24.5-65 mm. in length; spiracle a sht, very low on side, about 

 on the level of the mouth; in general very bronzy tadpoles; 



myotomes of tail musculature well indicated 



Scaphiopodidae. 



e. Teeth 6/6, 5/6, 6/5, 5/5; inner papillae present; spiracle 

 equidistant between eye and base of hind legs or vent ; 

 eye i . 4-1 . 8 nearer tip of snout than to the spiracle, 



