56 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 134 
Pedicle valve having the greater depth; strongly convex in lateral 
profile especially just anterior to the umbo. Beak long and strongly 
incurved. Umbo narrow, elongate. Median region swollen. 
Brachial valve convex in about the posterior third but flattened 
anteriorly. Anterior profile nearly flat. Posterolateral extremities 
deflected toward the pedicle valve, rounded. 
Measurements in mm.—Figured specimen, U.S.N.M. 125463, 
length 6.6., brachial length 5.2, maximum width 5.6, hinge width 3.4, 
thickness 4.0. 
Type.—Figured specimen, U.S.N.M. 125463. 
Locality — S46. 
Discussion—The small size of this Ambocoelia makes it unusual 
in the American Permian. It is longer than wide whereas most other 
species are wider than long. Ambocoelia arcuata Girty from the 
Phosphoria formation is a larger species and has a different outline. 
It is also not flattened anteriorly as is the Oregon species. Schell- 
wien’s A, telleri and Netschajew’s A. nucella are small species but 
they are strongly biconvex, quite unlike typical Ambocoelia or Cruri- 
thyris. The specimen figured herein is the only one in the Oregon 
collection ; consequently, it is impossible to tell whether it is a young 
form or an adult. 
Subfamily TricoNoTrETINAE Schuchert, 1893 
SPIRIFERELLA DRASCHEI (Toula) 
Plate 11C, figures 7-20 
Spirifera draschei Toura, Neues Jahrb. Mineral., Geol., Palaeont., p. 239, pl. 7, 
fig. 4, 1875. 
Spiriferella draschei (Toula) Branson, Geol. Soc. Amer. Mem. 26, p. 506, 1948. 
Spiriferina (Spiriferella) salteri TscHERNYSCHEW, Mém. Com. Géol., St. 
Petersburg, vol. 16, No. 2, pp. 128, 528, pl. 6, fig. 5, pl. 12, figs. 5, 6, 1902. 
Smaller than the type, moderately thin-shelled; longer than wide, 
with a pentagonal outline. Sides slightly convex, anterior margin 
subtruncate. Surface fascicostellate and pustulose; shell substance 
impunctate. 
Pedicle valve with beak strongly curved over dorsal umbo giving 
the shell a top-heavy appearance. Greatest curvature umbonally, 
convexity moderate in the anterior half. Sulcus originating at the 
beak and extending to the front margin, widening gradually ante- 
riorly to occupy about half the width at the front. Tongue long and 
sharply pointed. Flanks narrowly rounded and marked by about 5 
fascicles of costellae; sulcus marked by a few costellae. 
