PLATE II. 



Moon's age, 10 days 12 Jioars. Lick Observatory, 1S90. 



The most noteworthy changes as compared with PI. I are the great advance in 

 the development of the fields of very bright hue, and in the bands radiating from 

 them. These are most evident in the system of Copernicus. The system of Tycho 

 also l)egins to be evident. This vnlcanoi<l may be identified as the deep large crater 

 with a central cone near the border of the illuminated area. The general irregularity 

 of these light bands is well phown in those about Copernicus. So, too, the fact that 

 they are projections from an illuminated or lucent field about the vulcanoid. 



The relative absence of large vulcanoids on the maria is noteworthy. Those which 

 exist lie nearly, if not altogether, on fields of high ground which appear to have risen 

 above the floors of the maria and so escajied ir.elting. 



The problematical crater Liime now appears as a small white patch near the mid- 

 dle of the eastern side of the INI. Serenitatis. 



