Pg. 9, 17, 36 (table 6), pl. 27. Perilla member of Lowell formation of Bisbee group. Consists of the following divisions (ascending): (2d) friable light-yellow shale, 160 feet; (2c) brown crystalline limestone, 1 foot; (2b) light-yellow shale and argillaceous limestone, 85 feet; and (2a) brown crystalline limestone, 5 feet. Total thickness 251 feet. Underlies Pedregosa member (new) and overlies Quajote member (new); both of Lowell formation. Fossils, notably TRIGONIA MEARNSI, sp. nov., T. STOLLEYI Hill, ASTARTE ADKINSI, sp. nov., NEITHEA VICINALIS, sp. nov., and PTERIA PEREGERINA, sp. nov. Age is Early Cretaceous (Albian); LEYMERIELLA TARDEFURCATA standard ammonite zone.
[Occurs in the Ninety One Hills area, local name for hills in secs. 14 and 23, T. 24 S., R. 24 E., immediately north of International border in vicinity of International Monument No. 91, southeast of Bisbee Junction on Southern Pacific RR, Bisbee 15-min quadrangle, Cochise Co., southeastern AZ. Area includes type locality and standard section of Lowell Formation.]

Source: Publication; US geologic names lexicon (USGS Bull. 1200, p. 2988).