

Fig. ■ i. 



Fig. 



90 



Figs. 88, 89. — Reconstruction diagrams of the cranial cartilaginous skeleton in a double monster belonging to Cla I , . with union in the region of 

 the optic lobes. Fig. 88 is a view from above of the skeletal parts after removal of the rool cartilages b} a section passing horizontally through the olfi 

 and the auditory capsular cartilages. Fig. 88 also includes the mandibular and hyoid arches, which for diagrammatic purposes an n ted as wider 



than normal. The transverse lines numbered 35, 36,37, 38, indicate respectively the planes and levels of the various trans' tions shown in Pis. VIII., 



IX., figs. 35, 36, 37, 38. Fig. 89 represents the roof parts of the skull with transverse lines having the same meaning a n Fig. 88 (see < planatton under 

 PI. XVII. fig. 59). The general references to (.'lass I. will be found under PI. I. rig. 4. ( xapprox. 15.) 



FlG. 90. — Diagrammatic outline of the central cavities of the brain in the same double monster as that from which Figs. 88 and 89 were taken. The 

 transverse lini nave the ^.mie meaning as in these figures. The large composite cavity of the mid-brain (optic lobes) is seen to lead, in front, into the 

 1 nines of the two fore!. rains, and, behind, into that of the single medulla I see under PI. XVI 1 1, tig 70). 



47 

 48 



40 - - 



IG. 92 



Fig. .1 



Fit 



93- 



FIGS. 91-93. —Diagrams ol the cartilaginous cranial skeleton and ol the brain cavities in .1 double monster belonging to Class II., i.e. with union in tin- 

 region of the medulla. The numbered transverse lines are for the same purpose, and have the sane in. ig as in PI. XXI. tigs. 88-90. The genei il 



references to I b- II. are given und. ill: ■ ... See also under PI. XVII. tig. 61, XVIII. fig. 71. ( ■ approx. 1; I 



olfactory capsular cartilage, 

 trabeculae 1 



racl ordal cat tilages. 

 m trabei ulae in from 1 J the tv pituitai j pai 

 11 parachordals behind the pituitary spaces and the tendon of 

 rect. oc. ext. 



I.I I n KIM. IN All. I III FlGl Rl S. 



1 r 



kk' 



il il ■ 



out. r uid inner palat. 1 ptei 



hyomandibulai 

 period, '.hi 

 in the two pituitary 

 outer and innei Meckel's l»ars. 

 ,. hyoid ,11 



I. F. G. 



PL. XXI. 



