378 MEMOIRS OF THE CARNEGIE MUSEUM. 



EXPLANATION OF PLATE XLL 



Figs. 1-2. Eremophilus mutisii Humboldt. The air-bladders .show faintly as two 

 bags, one on either side of the origin of the vertebral column in fig. 2; and as a small 

 vesicle just above the column in fig. 1. The outlines are marked with a few dots. 



Figs. 3-4. Paracetopsis occidentalis (Steindachner). The air-bladder shows as a 

 large bag in fig. 3. A few points are placed in its wall to call attention to its outline. 



The tails in figures 1 and 3 are from the same negatives as the rest of these figures, 

 but have been printed heavier, as these portions are thin, and the negatives otherwise 

 quite faint. 



