The Fredericksburg Division of Texas ranges in age from the Middle Albian zones of subdelaruei or nitidus upward into the Upper Albian cristatum zone. The overlying Kiamichi Formation of the Washita Division is largely the equivalent of the varicosum zone. The base of the Upper Albian falls within the Goodland Formation of Texas. Previously the stratigraphic range of Venezoliceras has been misunderstood. In Texas this genus is restricted to the uppermost Middle Albian and the lowermost Upper Albian. Common occurrence in Texas with other South American ammonites, such as Oxytropidoceras buarquianum (White), O. douglasi Knechtel, Manuaniceras carbonarium (Gabb), and M. peruvianum multifidum (Steinmann), indicates that the range of Venezoliceras cannot be greatly different in South America. Venezoliceras is most abundant in the Comanche Peak and Goodland Formations but appears in the top of the Walnut Formation, and one species continues into the basal Kiamichi. In Texas Adkinsites is restricted to the Kiamichi Formation and most basal Duck Creek Formation, Washita Division. Oxytropidoceras first appears just above the middle of the Walnut Formation, in the Keys Valley Marl, and ranges upward through most of the Comanche Peak and Good-land Formations. Manuaniceras first appears in the Keys Valley Marl and ranges upward through the Comanche Peak and Goodland and Kiamichi Formations into the basal Duck Creek Formation. All of the specimens of Dipoloceras are from the Goodland Limestone of Tarrant County, Texas. Four Mojsisovicziinae ammonite zones are delineated below the lower Duck Creek zone of Craginites serratescens (Cragin); these, in descending order, are the zones of Adkinsites bravoensis (Böse), Manuaniceras powelli n. sp., Manuaniceras carbonarium (Gabb), and Oxytropidoceras salasi n. sp. Twenty-nine species of Albian Mojsisovicziinae of Texas represent the genera Adkinsites with 4 species, 2 new; Venezoliceras with 6 species, 3 new; Oxytropidoceras with 5 species, 3 new; Manuaniceras with 10 species, 6 new; and Dipoloceras with 4 species, one of which remains unnamed, and one of which is not described in the present work.

ABSTRACT The northern segment of the Edwards (Balcones Fault Zone) Aquifer is an important source of water for municipalities, industry, and landowners in central Texas. Rapid population growth in this part of Texas has increased interest in the north segment of the aquifer and heightened concerns about groundwater availability. The aquifer consists of Cretaceous limestone stratigraphic units that crop out along its western margin and dip toward the east. Groundwater primarily flows from the aquifer outcrop recharge zones toward discharge zones along perennial rivers and streams in the outcrop area and to a lesser extent toward deeper parts of the aquifer, eventually discharging by cross-formational flow to overlying stratigraphic units, such as the Del Rio Clay, Buda Limestone, and Austin Chalk. Groundwater isotope compositions in the aquifer indicate that groundwater flow is most active in the unconfined parts of the aquifer and that most recharge occurs during late fall and winter months, even though highest monthly precipitation occurs during the spring. Pumping from the northern segment of the Edwards (Balcones Fault Zone) Aquifer is ~6.8 × 10 7 L/d, having peaked at ~1.0 × 10 8 L/d in 2004, but still up from ~3.4 × 10 7 L/d in the 1980s. Most of this pumping (~90%) is for municipal uses. However, in the rural northern and heavily urbanized southern parts of the aquifer, domestic and manufacturing uses, respectively, account for a significant portion of total pumping.