191 



iScuTE. A large epidermal scale. 



Septum. A dividing wall, as that between the nasal passages. 



Snout. The portion cf the head in front of the eyes. 



Splenial. a bone at the hinder and inner part of the lower jaw ; oc- 

 casionally bearing teeth. 



Squamosal. A bone usually overlying the inner ear ; in snakes attached 

 to the hinder portion of the skull and supporting the quadrate. 



SuBCAUDALS. The large scales on the underside of the tail of a snake. 



SuPERCiLiARiES. The plates over the eye of a snake. See figure 9. 



Supraorbitals. Same as superciliaries. 



Symphysis. The union of two bones of opposite sides, in the middle 

 line, and with little or no motion. 



Tail. Portion of the body behind the vent. 



Temporal arch. A bony bar from the upper jaw to the quadrate, over- 

 lying the temporal muscle ; found in some tortoises. 

 Terete. Cylindrical and tapering. 



Urostyle. The rod-like posterior termination of the spinal column of 

 frogs. 



Vent. The opening outwardly of the cloaca. 



Ventral plates. The epidermal plates on the belly of snakes, etc. 



Vertebral scutes. The median row of plates on the back of a tortoise. 



See figure 11. 

 Vertical. See figure 9. 

 ViLLiFORM. Having the form or appearance of villi ; like the pile of 



velvet. 

 Vitta. a stripe. 

 Vomer. A bone lying in the roof of the mouth just behind the premax- 



iliary. One on each side of batrachia and reptiles. 

 Vomero-palatine. The united vomer and palatine. 



List of publications referred to in this work, together with the numbers 

 by which they are cited. 



1. Proceedings of the Academy of Natural Sciences of Philadelphia. 



2. Journal of the Academy of Natural Sciences of Philadelphia. 



3. Proceedings of the U. S. National Museum, Washington, D. C. 



4. Agassiz's Contributions to the Natural History of the United 



States. 1857. 



5. \yilkes' United States Exploring Expedition : Herpetology. 1858. 



6. Baird and Girard's Serpents of North America. 1853. 



7. Popular Science Monthly. 



