Mil 



PIIVLUM CHORD ATA 



12^ 



and the great ring-shaped (ninidar cariilafjc {an. c) which .sui)purts 

 the edge o\' tlie buccal ftmiicl. 



■ fzn c 



nct.a., 



- nc7t 



crv.c 



Fig. V95.— Petromyzon marinus. Dorsal (A), ventral (B), and sectional (C) views of skull. 

 The cartilaginous parts are dotted, a. <L c. ar.terior dorsal cartilage : mi. r. annular cartilage ; 

 au. c. auditory capsule; h. cr. /. basicranial fontancUe ; h. pi. basal plate; rii. r. cornual 

 cartilage ; cr. r. cranial roof ; n.a. neural arch ; na. ap. nasal aperture ; nch. notochord ; Nr. 1, 

 olfactory nerve ; Xr. j, .',, and S, foramina for the optic, trigeminal, and auditory nerves ; 

 Nf. 5\ fifth nerve ; off. c. olfactory capsule ; p. d. c. posterior dorsal cartilage ; p. Int. c. posterior 

 lateral cartilage ; sb. oc. a. sub-ocular arch ; st. p. styloid process. (After W. K. Parker.) 



The " tongue" is supported by a long impaired lingual cartilage 

 (Fiv. 794, ///. c), which probably answers to the united Meckel's 



