ALIMENTARY CANAL IN LEPIDOSIREN AND PROTOPTERUS. 503 
is enabled to do this by the already mentioned displacement 
of the oesophageal rudiment towards the left side. In speci- 
mens where the displacement of the oesophagus has not 
Text-fig. 9. 
Transverse section of a young Lepidosiren of stage XXXIV 
through the region of the glottis, a. Aorta, at. Atrium, c. o. 
Cement organ, gl. Glottis, n. Notochord, oc. r. Occipital rib. 
p./. Pectoral limb. ph. Pharynx, v. s. Ventricular septum. 
taken place to so great an extent, the lung grows round it in 
the manner to be described later. 
By stage XXXIV the hind end of the lung rudiment is dis- 
tinctly bilobed, the right lobe being for some time relatively 
