xii. 14 



MODERN AMPHIBIAN SKULLS 



329 



o.F P { ar F- 



cpt. %■ o.pt, cp- ps.^v. m 



apt. c.M. 



o.c I c - c - SALAMANDER 



bc.p. 



ICHTHYOPHIS 



Fig. 196. Skulls of amphibians. 



a., articular; be, basicranial fenestra; bc.p., posterior basicranial fenestra; c.c, carotid canal; 

 <-..V., Meckel's cartilage; c.p. coronoid process; cpt. pterygoid cartilage; c.r. process of 

 internasal plate; d. dentary; e.o. exoccipital;/. frontal ;fen.ol. olfactory fenestra; in. internal 

 naris;_/. jugal; m. maxillary; m.M. mento-Meckelian; ;;. nasal; o.c. occipital condyle; 

 o.f. optic foramen; o.p. occipito-petrosal; ope. operculum; o.pt. pterygoid bone; o.s. orbito- 

 sphenoid; p. a. pre-articular; par. parietal; p.f. prefrontal; p. I. palatine; p.m. premaxilla; 

 po.f. postfrontal (enclosing orbit); p.q. palato-quadrate; pr.ba. basal process; p.s. para- 

 sphenoid; p.v. prevoma; q. quadrate bone; sq. squamosal; st. stapes; /. tentacular groove; 



v. vomer. 



boxes, well seen in a tadpole's skull, are the central neurocranium 

 around the brain, and the olfactory and auditory capsules. Ossifications 

 occur especially at the points of compression stress, namely, around 

 the foramen magnum (the exoccipitals), where the auditory capsule 

 joins the cranium (the pro-otic), and at the base of the nasal capsules 

 (the mesethmoid). The paired occipital condyles are found only in 



