474 GEOLOGY AND PALEONTOLOGY OF CANAL ZONE


and the deeply sinuate diaphragm of C. labe'llata Deshayes (1861-63, p. 277, pl. 9, figs. 5-7, 1861; Oligocene, Paris basin) and other species. In unscuiptured surface and deeply sinuate diaphragm it is similar to C. centralis (Conrad), described on page 80, but the outline of that species is a smoothly tapering, low cone.
 The type is the largest of 15 specimens, two-thirds of which are immature, including the paratype, the only specimen that has an intact diaphragm. Though the limestone molds, described as C. cf. C. aperta, have the outline of C. li8 pa, their diaphragm is unknown.
 Occurrence: Gatuncillo formation (late Eocene), localities 9, 12 (identification doubtful both localities), 23b.
 Genus Trochita Schumacher (p. 80)
 Trochita spirata Forbes?
Trochita trochiformis (Born), erroneous designation for T.
 radians (Lamarck), Woodring, this report, p. 81, pl. 19,
 figs. 11-14, 1957 (Miocene, Panamii).
 After publication of chapter A, in a personal communication the late L. G. Hertlein, of the California Academy of Sciences, called my attention to Trochita spirata Forbes (1850 (1852), p. 271, pl. 11, fig. 1; living, Gulf of California; Reeve, 1859, species 8, pl. 2, figs. 8, 8a), which was overlooked when the fossils from Panamhwere identified. At a later date Olsson and Petit (1964, p. 565) expressed the opinion that the Gatun species is more suggestive of T. spirata than of T. 'radians.
 I am indebted to Dr. Hertlein for the loan of five specimens of T'. spirata f rom the coast of the state of Michoackn, M~xico. The dark-colored interior-a feature not available in fossils-readily distinguishes that species from T. radians. In addition, however, the ribs are more widely spaced than those of 7'. radians. The ribs of the smaller Gatun specimen (p1. 19, fig-s. 11, 12) are widely spaced, whereas those of the larger (pl. 19, figs. 13, 14) are closely spaced. That i s, the identification is equivocal.
 The status of the middle Miocene Venezuelan f ragment described as T. cf. T. radians (Jung, 1965, p. 497, p1. 66, figs. 1, 2) and of the early Pliocene Trinidad small specimens identified as T. radians (Jung, 1969, p. 473, pl. 47, figs. 12, 13) is uncertain, but they evidently are not T. spnrata. In any event the Trinidad form is the last western Atlantic Trochita.
 Occurrence: Lower part of Gatun formation (middle Miocene), localities 136, 136a.
 Trochita species
 Plate 72, figures 12, 16, 19
Trochita? cf. T. trochiformi8 (Born), Woodring, this report, p).
 37 (list), 81 (mentioned without designation), 1957 (Mbicene, Canal Zone).
 Small, low-spired to moderately high-spired. Ribs of moderate width and height, closely spaced.


 Height 12.5 mm, diameter 23.3 mm (figured specimen).
 Some 40 specimens of Trochita from the La Boca formation at locality 116a are in better condition than the six formerly available. All are small, their diameter ranging from 12 to 30 mm. Their ribs consistently are closely spaced. Whether this Trochita is related to T. radians, as it appears to be, is questionable. On zoogeographic grounds it is doubtful that a Miocene Caribbean species is closely related to a species now living in waters bathed by the Humboldt Current: an aspect not considered in chapter A.
 The ribs of the recently described late Miocene Florida species, T. floridana (Olsson and Petit, 1964, p. 563, pl. 81, figs, 2, 2a), the only species from eastern United States, not only are very closely spaced, they are also exceptionally high.
 Occurrence: La B~oca formation (early Miocene), localities li5a, 115b (Trochita? sp. for both localities, assigned to Culebra formation in chapter A), 116, 116a.
 Genus Crucibulum Schumacher (p. 82)
 Subgenus Crucibulum s.s.
 Crucibulum (Crucibulum) spinosum (Sowerby) Plate 73, figure 7
Calyptraea spinosa Sowerby, The genera of recent and fossil
 shells, fase. 23 [p. 142], pl. 151, fig. 4, 1824 (age and locality
 not specified).
Cruoibulum spinosumt (Sowerby), Dali, U.S. Natl. Mus. Proc., v.
 37, p. 173, 233, 1909 (living, California to Chile).
Orucibulum (Crucibulum) spino sum (Sowerby), Olsson, Neogene
 mollusks from northwestern Ecuador, Paleontological Research Inst., p. 196, p1. 34, fig. 5, 1964 (Miocene, Ecuador). Cruoibuturn auriculatum Chemnitz, Sowerby, Monograph of the
 family Calyptraedae: in Thesaurus conchyliorum, p. 60, p1.
 3, figs. 7-14, 1883 (living, Central America).
Cruotbulum piliferurn Guppy, Sdi. Assoc. Trinidad Proc., pt. 3,
 p. 172, 1867 (Pliocene, Trinidad) ; reprint, Bull. Am. Paleontology, v. 8, no. 35,,p. 51, 1921.
Crucibulurn (Grucibulum) pitiferurn Guppy, Jung, Bull. Am.
 Paleontology, v. 55, no. 247, p. 475, p1. 47, figs. 14-16, 1969
 (Pliocene, Trinidad).
 Small, subcircular, low-spired, apex subcentral. Capulid protoconch and about first half of first Postprotoconch whorl smooth. Remainder of shell sculptured with radial ribs of two ranks: (1) narrow, widely spaced ribs bearing low broken spines, generally appearing as stubby tubes or vaulted scales; (2) low, crowded, more or less irregular, minutely nodose ribs, generally trending at low angle to first order ribs. Cup broken, except basal part.
 Height 9.7 mmi diameter 15.2 mm. (figured specimeni) A small nicked Crucibiuln, in the large collection from the lower part of the Gatun formation at locality 138c is identified as C. 8pinoswm, now living in eastern


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