The lead and zinc deposits in the Upper Cambrian rocks of central Texas are reviewed in the light of new detailed information. Included are analytical data for all deposits, detailed stratigraphic sections of the Cambrian rocks, and maps at a scale of 4 inches to the mile.

A deposit of phosphorite, estimated to be 11 feet thick, was found March 26, 1952, while the writer was mapping ancient sink fillings and collapse structures within the outcrop area of the Honeycut formation south of Marble Falls, Texas.

Sixty-eight species of trilobites, 10 species of inarticulate brachiopods, two species of articulate brachiopods, one ostracode and fragments of sponges, pelmatozoan echinoderms and unidentifiable organisms constitute the faunas of the Riley formation.

Chemical analyses show that a reef approximately 100 feet thick in the lower portionof the Marble Falls limestone near Marble Falls, Burnet County, Texas, is exceptionally pure.

Steeply dipping shales and interbedded sandstones presumably of the Ouachita facies have been discovered along the Colorado River in Burnet and Travis counties, Texas. Previously the Ouachita facies was known in Texas only from bore-hole samples.