By Michael A. Murphy
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Extra resources for Paleontology and stratigraphy of the Lower Chickabally Mudstone (Barremian-Aptian) in the Ono Quadrangle, Northern California
1). Anderson (1938, p. 203) assigned his genus to the Family Hemihop litidae because of the character of the suture and ornamentation. An assignment close to Hemihoplites seems more reasonable than Wright's (1957, p. L208) subsequent classification of it in the Ancyloceratidae because of its whorl shape and stratigraphic position, as well as the char acters cited by Anderson. Wright was probably mislead by Anderson's (1938, p. 203) interpretation which claimed that the many fragmental, uncoiled shells commonly associated with S.
X 40 10 1 1 1 1 1 20 30 40 50 60 Fig. 23. Measurements of specimens of Shasticrioceras from the Chickabally Member, Ono Quadrangle. J 70 44 University of California Publications in Geological Sciences River Road section, is uppermost Barremian and probably also lowest Aptian. The reasons for this assignment are given in the section on corre lation. As presently understood, it barely overlaps in its lower part with the local range zone of S. roddai n. sp. The last recorded occurrence is about 15 feet below the Huling Tongue in the Roaring River Road section.
2) For synonymy of Toxoceratoides royerianus (d'Orbigny), see Casey, 1961, p. 78. The shell is of medium size, probably with labeceratid coiling. The ornamentation of the specimen is similar to that found in the neotype of T. royerianus as figured in Casey ( 1 9 6 1 , p. 79, fig. 30a-c). The main dif ferences are that the California specimen has less oblique ribbing on the shaft, the ribs on the hook are more distant and the specimen is somewhat larger and more expanded in the hook (fig. 18). The variation that occurs in various specimens assigned to T.