568 
DE. A. GUNTHER’S DESCRIPTION OF CERATODUS. 
n. 
0 . 
p. 
q, q 1 . 
r. 
s. 
d. 
t. 
VO. 
x 1 and x". 
Carotis. 
Ramus recurrens. 
Arteria coeliaca. 
Arteria subclavia. 
Anastomosis between arteria subclavia and vena cava superior. 
Vena cava superior dextra. 
Vena cava superior sinistra. 
Semiobliterated branch of vena cava superior. 
Fifth branchial arch. 
As in fig. 8. 
PLATE XXXVIII. 
Fig. 1. Ventral aspect of upper half of lung, with the system of the pulmonal vein 
blood-injected. Natural size. 
a. Smooth median band. 
b. Anterior end of left half of lung. 
e. Vena pulmonalis; e 1 , right branch. 
f Arterial (1) blood-vessel ; right branch. 
g. Place where this vessel breaks up into several terminal branches. 
gl. Glottis. 
ce. Part of the oesophagus slit open. 
Fig. 2. Lower half of the lung, slit open along the ventral median band, to show the 
internal structure. 
c. Posterior end of left half of lung. 
d. Dorsal median line of lung running along the aorta. 
Figs. 3-9. Vertical sections through the first (3), fourth (4), fifth (5), fifteenth (6), 
twenty-ninth (7), forty-eighth (8), and sixtieth (9) sets of apophyses, to show 
the relative extent of bone and cartilage (half the natural size). The ossified 
portions are represented black, the cartilaginous only slightly shaded. 
a. Central cylinder of notochord. 
b. Notochord. 
c. Confluent neur- and htemapophysis of first set. 
c' . Neurapophysis, cartilage. 
(f. Hfemapophysis. 
d. Medullary canal. 
e. Neurapophysis, bony part. 
e'. Canal for ligamentum longitudinale, 
f. Neural spine. 
g. Interneural first. 
h. Interneural second. 
