168 J. P. Kimball on the Silver Mines of Sta. Eulalia, Mexico. 
The other workings of this.group are on the east side, and 
further toward the head of the ravine, occupying different beds 
in the limestone and pursuing productive courses of ore. The 
principal are Chiguihwite, Rosario, Gertrudis and S. Lazaro. 
__ Dotores Grovup.—The cafion of Dolores is a deep gorge cut- 
ting almost perpendicularly the axis of the limestone uplift or 
boss e clifis thus formed, expose on either side a perfect 
section of bare limestone strata. Its course is very nearly west- 
ward, and its head opposite and very near that of the Santo 
omingo arroyo. Together the two water-courses describe a 
his 
regular sinking of about the same age and depth as the latter, 
and communicates with it by deep workings. Its mouth is near 
the top of the limestone formation. 
_ The Dolores, present working, is a sinki iz of the same deserip- 
tion as the A ome with the lower ante of which, and 
thereby with those of 
dwel — built strong for defense, indicate a former 
establis 
P 
no percolation being sensible even in the dee 
he world have a more task. The cost of raising the o 
