Hurler — Flerpetology of Missouri. 273 



EXPLANATION OF ILLUSTRATIONS. 



Plate XVIII. — Fig. 1. Open mouth of Avihystovia tigrinum Green. 

 Vt. Vomerine teeth. Pt. Parasphenoid bands of teeth. Ch. Choanae. 

 T. Tongue. — Fig. 2. Open mouth of Amhystoma microstomiim Cope. — 

 Fig. 3. Open mouth of Plcthodon glutinosus Green.— Fig. 4. Open 

 mouth of Spelerpes longicaiidus Green.— Fig. 5. Head of Spelerpes, 

 showing mushroom shaped tongue.— Fig. 6. Roof of mouth of Spelerpes 

 maculicaudus Cope. Fig. 7. Open mouth of Typhlotriion spelaeus 

 Stejn.— Fig. 8. Open mouth of nicmijiUjlm viridescc7is, showing the 

 parasphenoidal teeth arranged in V form.— Fig. 9. Open mouth of Rana 

 catesbiana Shaw. Ch. Choanae. E. Opening of eustachian tube from 

 ear. EI. Elevations caused by the eye balls. F. Food passage. L. 

 Opening to larynx and lungs. Vc. Opening into vocal sac. Vmt. 

 Vomerine teeth. T. Tongue. 



Plate XIX.— Pig. 1. Ventral vlev.- of shoulder girdle of Rana cates- 

 hiana. The shoulder girdle is grown together in front, and the chest 

 is not expansible (firmisternal type). Om. Omosternum. CI. Clavicle. 

 Sc. Scapula. H. Humerus. Co. Coracoid. Ep. Epicoracoid. Me. Metas- 

 ternum. Xs. Xiphisternum. — Fig. 2. Ventral view of shoulder girdle 

 of Bufo americana. The shoulder girdle is overlapping in front, and 

 the chest expansible. (Arciferous type.)— Fig. 3. Dorsal view of 

 pelvis girdle of Rana catesbiana. Sd. Sacral diapophyses, cylindrical. 

 II. Ilium. Us. Urostyle. Is. Ischium. Fig. 4. — Dorsal view of pelvic 

 girdle of Bufo americana. Diapophyses of sacral or ninth vertebra 

 dilated. 



Plate XX. — Fig. 1. Rana areolata. a. Hind foot. b. Fore foot. — Fig. 

 2. Rana clamatans. a. Hind foot. b. Fore foot. — Fig. 3. Rana cates- 

 biana. a. Hind foot. b. Fore foot.— Fig. 4. Acris grylliis. a. Hind 

 foot. b. Fore foot. — Fig. 5. Chorophihts triseriaUiS. a. Hind foot. b. 

 Fore foot. — Fig. 6. Hyla versicolor, a. Hind foot. b. Fore foot. 



Plate XXI. — Fig. 1. Dorsal view of head of Elaphe obsoletu.<i. a. 

 Rostral, b. Internasals. c. Prefrontals, d. Frontal, e. Supraorbitals, 

 f. Parietals. z. Dorsals. — Fig. 2. Side view of the same head. g. Nasals. 

 h. Loral, i. Anteorbitals. j. Postorbitals. k. Upper labials. 1. Lower 

 labials m. Temporals. — Fig. 3. Ventral view of the same head. n. 

 Mental, o. Anterior chin shields, p. Posterior chin shields, g. Ven- 

 trals. — Pig. 4. Skull of Natrix natrix. (Boulenger.) pm. Premaxil- 

 lary. m. Maxillary, n. Nasal, pi. Palatine bone. f. Frontal, ptf. 

 Postfrontal. p. Parietal, q. Quadrate, pg. Pterygoid, ar. Articular, d. 

 Dentary. Pfr. Prefrontal. Ca. Columella auris. ste. Suprat.emporal. — 

 Pig. .5. Skull of Crotalus. m. Maxillary, a. External pterygoid bone, 

 b. Internal pterygoid bone. c. Palatine bono. e. Lachrymal bone. f. 

 Pangs. — Fig. 6. Head of Pit Viper. Side view. n. Lower labials, o. 

 Upper labials, g. Loral, r. Nasal, no. Nostril, p. Pit. e. Eye. pr. 



