DR. A. GUNTHER’S DESCRIPTION OE CERATODUS. 
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PLATE XXXV. 
Structure of the Skull (continued). Figures 1-3 are § the natural size. 
Fig. 1, Lateral view (the facial cartilages are removed). 
Fig. 2. Vertical section of the skull made along the median line, showing also the inner 
surface of the mandible and molars. 
To facilitate a comparison with figs. 1-3 of Plate XXXIV., the same letters 
have been used in these figures whenever possible. 
a. Scleroparietal. 
ac. Acoustic membrane. 
b. Ethmoid. 
V. Foramen olfactorium. 
bh. Basihyal. 
c. Frontal. 
d . Process of frontal for its connexion with the pterygo-palatine bone. 
cd. Section through notochord ; cd end of central cylinder. 
ch. Ceratohyal. 
co. Upper coracoid ; co\ lower coracoid. 
d. Tympanic lamina. 
e. Infraorbital ossifications. 
f. Facial cartilage, turned upwards in fig, 1, and with its end longitudi- 
nally cut through in fig. 2. 
(jh. Glossohyal. 
h. Operculum. 
1L Suboperculum. 
he. Humeral cartilage. 
I. Pterygo-palatine ; l ', symphysis of the pterygo-palatine bones. 
la. Lower labial cartilage. 
II. Ligamentum longitudinale. 
m. Foramen for 1st and 2nd ramus of nervus trigeminus, 
m". Foramen for 3rd ramus of nervus trigeminus and part of nervus acus- 
ticus. 
me. Median cartilage of scapular arch, cut through its median line. 
ml. Molar teeth, viewed from the inside of the oral cavity. 
mt. Insertion of musculus temporalis. 
o. Basale. 
ol. Passage for olfactory nerve. 
op. Foramen opticum. 
p. Cartilaginous roof of gill-cavity. 
pt. Pituitary gland. 
g. Os quadratum. 
