PHYLUM CHORDATA 



127 



and the great ring-shaped anmolar cartilage {an. c.) which supports 

 the edge of the buccal funnel. 



o' dc 



na.a 



p cLc 



nc7t 



plul.c 



crv.c 



Pig. T9.5.— Petromyzon marinus. Dorsal (A), ventral (B), and sectional (C) views of skull. 

 The cartilaginous parts are dotted, a. d. c. anterior dorsal cartilage ; an. c. annular cartilage ; 

 au. c. auditory capsule ; b. cr. f. basicranial fontanellc ; h. pi. basal plate ; m. c. cornual 

 cartilage ; cr. r. cranial roof ; n.a. neural arch ; 71a. aj}. nasal apei'ture ; nch. notochord ; Nv. 1, 

 olfactory nerve ; Nv. S, 5, and 8, foramina for the optic, trigeminal, and auditory nerves ; 

 Nv. 5', fifth nerve ; off. c. olfactory capsule ; p.d. c. posterior dorsal cartilage ; -p. lat. 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 unpaired lingua-l carlilage 

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



