OF THE PLATES. 473 



w.w. Os Articulare of the lower jaw. 



X. Os Dentale of the lower jaw. 



z. A small portion of the Supra-Angulare. 



There are also two other bones on the internal face 

 of the head, which it has been found impossible to re- 

 present in these figures. 

 Fig. 4, 5, 6. Head of a Rattlesnake exhibiting the osteology 

 of the head of an ordinary venomous serpent. 



The letters here designate the same bones as in the figure of 

 the head of the Python, and the difference in their proportions, 

 particularly those of the maxillary and pterygoid bones, are thus 

 easily observed. 



Plate VI. Head of a Codfish, showing the osteology of the 

 head of fishes in general. 



Fig. 1, the cranium seen from above; 2, from beneath; and 3, 

 the profile of the entire head. 



a.a.a. Single Os Frontis proper. 



b.b. Anterior Ossa Frontis. 



c.c. Posterior Ossa Frontis. 



d.d. Ossa Parietalia. 



e. Single Interparietal. 



e. Its crest. 



//. Superior Ossa Occipitis. 



g.g. Lateral Ossa Occipitis. 



h.h. Ossa Mastoidea. 



i. Inferior Os Occipitis. 



k. The Ethmoid. 



I. Vomer. 



m. Sphenoid. 



n.n. Petrous portions of the Temporal bones. 



0.0. Great wings of the Sphenoid. 



p.p. Small wings of the same bone. 



q. Intermaxillaries. 



r. Maxillary. 



s. Os Nasi. 



t. Inferior Os Turbinatum? 



u.u. Infra-orbitals. 



v.v. Os Temporis. 



w. Tympanum. 



X. Ossa Transversa. ~ 



y. Pterygoideus Internus. 



z. Jugal. 



* Preoperculum. 

 Vol. II. 3 K 



