188 
circulare. 
eboreum. 
Pars 15 
1907 Pecten (Plagioctenium) circularis Eldridge - Arnold, (339) 
T. XXXV, fig. 4. 
1918 Pecten (Plagioctenium) circularis v. Teppner, (312). 
Pliocan. Nordamerika. 
Cooperi Arnold. 
1906 Pecten (Plagioctenium) Cooperi Arnold, (139) p. 124, 125, T. 49, 
fig. 2—4. 
Pliocan. Kalifornien. 
deserti Conrad. 
1855 Pecten deserti Conrad, Desc. Fos. and Shells, House Doc., 129, 
July, p. 15. 
1856 Pecten deserti Conrad, Descriptions of the fossil shells. Pac. 
E. E. Eept., V, App., p. 317 — 330, T. V, fig. 41. 
1888 Pecten deserti Cooper, Catalogue of Californ. fossils, Seventh 
Ann. Eept. Cal. State Mineralogist for 1887 Sacramento, p. 257. 
1898 Pecten (Plagioctenium) deserti Dall, (308) p. 703. 
1906 Pecten (Plagioctenium) deserti Arnold, (139) p. 85, T. XXVI, 
fig. 1, 2, 2a, 3, 4, 4a. 
1909 Pecten (Plagioctenium) deserti Arnold, (330) p. 33. 39, 76, 
T. XXVI, fig. 3, 4. 
1909 Pecten deserti Dall, (272) App. X, Conrad, p. 181. 
1909 Pecten deserti Dall, (272) App. VI, Conrad, p. 167. 
1910 Pecten (Plagioctenium) deserti Arnold-Anderson, (341) p. 126, 
129, 132, T. 48, fig. 3, 4. 
Miocan. Nord- und Mittelamerika. 
discum Conrad. 
1857 Pecten discus Conrad, Eeport on the paleontol. of the survey, 
Pacific E. E. Eept., VII, pt. 2, p. 190, T. 3, fig. 1. 
1869 Pecten discus Gabb, Geolog. Survey of California, Paleonto- 
logy, II, p. 122. 
1888 Pecten discus Cooper, Catal. of Californian fossils, Seventh. 
Ann. Eept. Cal. State Min., p. 258 (pars). 
1888 Pecten pabloensis Cooper, ibid., p. 258 (pars). 
1898 Pecten (Chlamys?) discus Dall, (308) p. 704 — 706. 
1906 Pecten (Plagioctenium) discus Arnold, (139) p. 86, 87, T. XXVII, 
fig. 1, la, 2—4. 
1909 Pecten discus Dall, (272) App. X. Conrad, p. 181. 
Mittelmiocan. Obermiocan. Nord- und Mittelamerika. 
eboreum Conrad. 
1833 Pecten eboreus Conrad. Am. Journ. Sci., XXIII, p. 341. 
1840 Pecten eboreus Conrad, Fossil of the Medial Tertiarv p. 48 
T. XXIII, fig. 2; T. XXIV, fig. 3. 
1843 Pecten wicenarius Conrad, Proc. Acad. Nat. Sci. Philadelphia 
I, p. 306. 
1844 Pecten Holbrookii Eavenel, ibid., II, p. 96. 
1846 ?Pecten microplenra H. C. Lea, Trans. Am. Phil Soc IX 
p. 245. T. XXXV, fig. 32, 
1855 Pecten comparilis Tuomev and Holmes, Pleioc. Fos. S Car 
p. 29, T. XI, fig. 6—10. 
