Middle Jurassic (Bajocian) Eastern Oregon

PLATE 10
[Figure about four-fifths natural size]
FIGUlu: 1. Sonninia (Euhoploceras) modesta Buckman (p. 62).
Laleral view of large laterally crushed hypotype, CAS 13467 from Luphers'
loc. 610 in Weberg Member of Snowshoe Formation. Adoral fifth or
outer whorl is rwnseptate and presumably represents part of the adult
body chamLer. Note vertical umbilical wall, abrupt umbilical edge,
widening of umbilicus during growth, general smoothness of internal
mold, and presence of broad radial undulations. Weathering accounts
for some nf the smoothness on the adapical part of the outer whorl.
Note resemblance to S. simplex Buckman (1892, pl. 70, figs. 2- 4), S.
substriata Buckman (1892, pl. 71, ftg. 6), S. parvicostata Buckman (1892,
pl. 7;), figs. 3-5), S. modesta Buckman (1892, pl. 68), and S. nuda Buckman
(1893, pl. 82, figs . 3, 4).