GEOLOGY AND PALEONTOLOGY OF CANAL ZONE


the type locality of Neritina (Puperita) figulopicta Maury (1917, p. 152, pl. 24, fig. 10; Cercado formation, Dominican Republic), presumably conspecific with N. figulopicta, has the callus and the prevailing color pattern of N. virginea and evidently belongs to that species.
 The fossils from the Gatun formation, and also those from the Culebra formation referred to Neritina sp., may be immature shells of species as large as N. virginea, or may be mature shells of small species. As shown by numerous specimens, N. chipolana Dall (1890-1903, pt. 2, p. 422, pl. 23, fig. 19, 1892), from the Chipola formation of Florida, is a small species (height 5 millimeters) comparable in size to the fossils from Panam6. It has a color pattern of widely spaced, irregularly curved or zigzag, axial lines, or widely spaced groups of two to five such lines. The callus is thinner than that of the fossils from Panamd and is indented by a ledge adjoining the base of the columellar lip.
 Occurrence: Middle part of Gatun formation (middle Miocene), western area, localities 161c, 170a.
 Family THIARIDAE?
 Genus Hannatoma Olsson?
 Olsson, Bull. Am. Paleontology, v. 17, no. 63, p. 80, 1931. Type (orthotype): Melanatria? gesteri Hanna and Israelsky,
 Oligocene, Perd.
 Hannatoma? cf. H. emendorferi Olsson Plate 14, figure 3
 Of small size for genus Hannatoma, Mesalia-like in outline. Preserved spire whorls preceding penult sculptured with two strong flangelike spirals, the posterior spiral adjoining the suture, the anterior spiral lying a little in front of middle of whorl. Penult bearing also a narrower spiral emerging from anterior suture. Body whorl broken; aperture and growth line unknown.
 Height (incomplete) 35.5 mm, diameter (incomplete) 15 mm (figured specimen).
 An incomplete silicified fossil from the Gatuncillo formation in the Rio Casaya area is doubtfully identified as a species of Hannatoma comparable to H. emendorferi, which occurs in the Eocene of Peru, in strata that were thought to be of Oligocene age when the species was described (Olsson, 1931, p. 82, pl. 15, figs. 3, 8). Unfortunately the aperture is not preserved and the growth line is not discernable. The spirals are more flangelike than those of H. emendorferi and of a closely allied, or identical, form found in strata of late Eocene age in eastern Colombia and western Venezuela.
 Some species of Mesalia, including forms of the widely distributed Eocene M. fasciata (Lamarck) (Cox, 1930, p. 157, pl. 18, figs. 2, 3) have two flangelike spirals on


spire whorls. The spirals, however, are narrow and the posterior one does not adjoin the suture.
 Occurrence: Gatuncillo formation (middle Eocene), Rio Casaya area, locality 38.
 Family LITTORINIDAE
 Genus Littorina F6russac
F6russac, Tableaux syst6matiques des arimaux mollusques, p. XI (vernacular name "littorine" for "paludines marines", five species of which are listed or p. ix-x with the designation "Paludina, marine"), p. XXXIV ["Littorine, Littorina" a& subgenus of "Paludine, Paludina, F6russ. (fluv. et marin)",
 no species mentioned], 1822.
Type (logotype, de Blainviile, Dictionnaire des sciences
 naturelles, v. 56, p. 98 ("le genre Littorine, ayant pour type le T. littoreus"), 1828: Turbo littoreus Linn6, Recent, western
 Europe.
 F6russac gave no definition of the name Littorina and cited no species under it. On other pages, however, he listed five species as marine species of Paludina and on still another page he stated that he was forming a subgenus under the name littorine for marine paludines, which constituted the genus Trochus of Adanson. These vernacular names are the same as those used oni page XXXIV with the corresponding formal names-1 This is a roundabout method, involving vernacular names, of determining what species Ferussac included under Littorina.
 Littorina aff. L. angulifera (Lamarck)
 Plate 16, figures 1, 2
 Of medium size, high-spired. Periphery of body whorl sharply angulated at beginning of whorl, obtusely angulated toward outer lip. Narrow spiral grooveG visible on preserved parts of outer shell. Columellar lip excavated.
 Height (practically complete) 12 mm, diameter 8.5, mm (figured specimen).
 An imperfect specimen of the genus Littorina was found in the uppermost part of the Culebra formationin an association of brackish-water and marine species.1 Much of the shell is not preserved, including the edge of the basal and outer lips. The sculpture, however,, remains on two patches of outer shell. It shows to best advantage on the base of the body whorl adjoining the thin wash of parietal callus.
 Imperfect as this fossil is, it is of exceptional interest, as it is the first Tertiary Littorina to be recorded from the Caribbean region and it extends back to the early, Miocene the lineage of a living Caribbean species, L. angulijera (Lamarck) (Bequaert, 1943, p. 23, pl. 7). The fossil so closely resembles small angulated specimens of L. angulijera that unequivocal assignment to that species may be justified. The columellar lip is wider than on most small shells of L. angulifera ex-4


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