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MILLER. 



DESCRIPTION OF PLATE VII. 



Fig. I. Lung of Necturus lateralis, inflated and dried. Natural size. The left 

 lung is cut open ; the right is in outline. The blood-vessels were injected, and the 

 relation between the artery and vein is well shown. 



Fig. 2. Lung of Rana sylvatica. Medium sized animal, prepared as Fig. i. 

 One half of the left lung is represented. The honey-combed appearance is well 



shown. 



Fig. 3. Lung of Bascanion constrictor. Natural size ; the posterior six centi- 

 meters are not shown. Note the smooth surface of the posterior portion ; the 

 gradual thickening of the wall in anterior portion, due to the gradual deepening of 



the air-sacs. 



Fig. 4. A portion of Fig. 3- X 5 times. The appearance of the air-sacs as one 



looks into them, is clearly shown. 



Fig. 5. Lung of Heloderma suspectum. Natural size. The position of the 

 bronchus as continued in the interior of the lung is indicated by the red markings. 



Fig. 6. Lung of Graptemys lesneuri. Natural size. The course of the bron- 

 chus within the lung is indicated by the blue thread. Note the simpler character 

 of the posterior sac. 



Fig. 7. Lung of Crocodilia ; 87 cm. long. Natural size. A little below the 

 center the breaking up of the bronchus into atria is shown. The two arrows at 

 the upper part of the figure pass through air-sac passages and indicate the com- 

 munication of two air-sacs with the elongated atrium. The finer openings are air- 

 cells. 



Fig. 8. A transverse section through the opposite lung of the same specimen 

 as shown in Fig. 7. The plane of the section is through the terminal bronchus ; 

 the vestibules and a few of the atria are shown ; also the air-sacs and air-cells. 



