PLATE 7 



EXPLANATION OF FIGURES 



41 Section through the Malpighian body of one of the oldest specimens 

 (Myxine no. 10), showing degeneration of the glomerulus. Camera lucida, X 

 19. 



42 Section through the Malpighian body of pronephros of a young Myxine 

 (no. 18), showing double glomerulus. Camera lucida X 50. 



43 Section through Malpighian body of pronephros of a young Myxine (no. 

 18), showing the glomerulus exposed to the pericardial cavity through a large 

 opening and resembling a glomus. Camera lucida, X 50. 



44 Transverse section through mesonephros of Bdellostoma no. 17, cut in 

 mid-region of body cavity, showing relation of the ducts to blood vessels and 

 peritoneum. 



45 Dorsal view of the excretory system of Bdellostoma no. 16. One-half 

 natural size. Male. 



46 Dorsal view of the excretory system of Bdellostoma no. 15. One-half 

 natural size. Female. 



47 Dorsal view of posterior ends of mesonephric ducts of Bdellostoma no. 

 16. Natural size. 



48 Side view of posterior end of left mesonephric duct of Bdellostoma no 16. 

 Natural size. 



152 



