Hurler — Herpetology of Missouri. 273 



EXPLANATION OF ILLUSTRATIONS. 



Plate XVIII. — Fig. L Open mouth of Avibystovia tigrinuvi Green. 

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

 T. Tongue. — Fig. 2. Open mouth of Ambystoma microstovium Cope. — 

 Fig. 3. Open mouth of Plethodon gJutinosus Green.— Fig. 4. Open 

 mouth of SpeJerpes longicaudus Green.— Fig. Tu Head of SpeJerpes, 

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

 7naculicaudus Cope. Fig. 7. Open mouth of Typhlotriton spelaeus 

 Stejn.— Fig. 8. Open mouth of Dicmyctylus viridescens, showing the 

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

 catesbiana Shav.-. Ch. Choanae. E. Opening of eustachian tube from 

 ear. El. 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.^ — Fig. 1. Ventral view of shoulder girdle of Rana cates- 

 biana. 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 Biifo 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 gryllus. a. Hind 

 foot. b. Fore foot. — Fig. 5. Chorophilus triseriattis. 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 Elaplie obsoletus. 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. 1. 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. — Fig. 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. Supratemporal. — 

 Fig. 5. Skull of Crotahts. m. Maxillary, a. External pterygoid bone, 

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

 Fangs. — 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. 



