GASTROPODS: TROCHID

 Both "Lupia" perovata and "Amauropsis" jacksonensis have been considered high-spired species of Crommium (Palmer, 1937, p. 136, pl. 14, figs. 5, 9; Harris and Palmer, 1946-47, p. 256, pl. 30, fig. 5, 1947). Should the names Euspirocrommium or Pachycrommium prove to be inappropriate for these high,spired species that evidently are related to Crommium, Pseudocrommium (Clark, in Clark and Durham, 1946, p. 18; type (orthotype): Pseudocrommium carmenensis Clark), based on a late Eocene species from Colombia, is available for them and has recently been used for them (Richards and Palmer, 1953, p. 27). Occurrence: Marine member of Bohio(?) formation (late Eocene or early Oligocene), Gatun Lake area, localities 40a, 40b, 40d, 41.
 Pachycrommium? cf. P.? trinitatensis (Mansfield) Plate 16, figure 11
 Large, shouldered, strongly inflated. Spire high, turreted. Aperture moderately elongate. Other apertural features unknown.
 Height (incomplete) 50 mm, diameter (exaggerated by crushing, 39 mm (figured specimen).
 Molds of a large high-spired globularine, which occur in the middle member of the Caimito formation in the Gatun Lake area and in the Culebra formation, resemble the type of "Amauropsis" trinitatensis (Mansfield, 1925, p. 58, pl. 10, figs. 4, 5). The type of that species is a mold from early Miocene strata in Trinidad. Mansfield's (1937, p. 177, pl. 9, fig. 7) "Amauropsis" aff. "A." burnsii meridionalis Pilsbry, a late Oligocene form represented by molds from Georgia and Florida, also resembles the type of "Amauropsis" trinitatensis. "Amauropsis" burnsii saeridionalis (Pilsbry, 1922, p. 387, pl. 34, figs. 23, 24) occurs in the Miocene of the Dominican Republc. Despite its wide deep channel
-adjoining the suture, it appears to be a Pachycrommium. Mansfield's (1940, p. 223, pl. 27, fig. 8) late Oligocene 1 -hycrommium? sp., a mold from the lower part of Chickasawhay marl, has a similar sutural channel, but is larger and has a higher spire. Though "Amauropsis'" burnsii meridionalis has a sutural channel like that of the Chipola species "Polinices (Amauropsis)" burnsii Dall (Gardner, 1926-47, p. 557, pl. 59, fig. 12, 1947), a close relationship between the two forms is doubtful. The Chipola species has a wide expanded aperture and thickened outer lip. It is a remarkable globularine.
 If the unknown apertural features of both "Amauropsis" trinitatensis and the fossils from Panama' could be ignored, the fossils from Panama would be unequivocally identified as the Trinidad species. The outline of the figured mold is distorted by dorso-ventral crushing. Should "Amauropsis" trinitatensis prove to be a Pachycrommium, it would be the largest species of the


AE TO TURRITELLIDAE 97

genus. "Natica" phasianelloides d'Orbigny [1852(?), p. 9, pl. 1, fig. 7] may be an earlier name for it.
 Occurrence: Middle member of Caimito formation (late Oligocene), Gatun Lake area, locality 60. Culebra formation (early Miocene), Gaillard Cut, locality 108c.
 Pachycrommium? cf. P. guppyi (Gabb) Plate 16, figure 12
 Of medium size, strongly inflated, strongly shouldered. Spire high, strongly turreted. Gently sloping shelf extends from suture to shoulder. Apertural features unknown.
 Height (not quite complete) 27 mm, diameter 21.5 mm (figured specimen).
 The Culebra formation yielded three incomplete high-spired globularines. The most nearly complete specimen, which is figured (and probably also the other two) is comparable in outline to the strongly shouldered form of Pachycrommium geppyi (Pilsbry, 1922, p. 386, pl. 34, figs. 25-27). P. guppyi occurs in the early Miocene Baitoa formation of the Dominican Republic and also in the middle Miocene Cercado and Gurabo formations. Mansfield (1937, p. 174) considered "Amauropsis" foridana Dall (1915, p. 108, pl. 5, fig. 11), a small Pachycrommium from the early Miocene Tampa limestone of Florida, to be indistinguishable from P. guppyi. P. floridanum, however, has a more expanded aperture and correspondingly more inflated body whorl. The middle Miocene Oak Grove form, P. dodonum Gardner (1926-47, p. 557, pl. 59, figs. 4, 13, 1947), agrees with the strongly shouldered form of P. geepyi.
 Though Pachycrommim guppyi occurs in formation correlated with the Gatun formation, the genus has not been found in the Gatun formation. Pachycrommium? cf. P. guppyi is the youngest of the high-spired globularines in the Canal Zone.
 Occurrence: Culebra formation (early Miocene), Gaillard Cut, localities 112, 115a.
 Family TURRITELLIDAE Genus Turritella Lamarck
 Lamarck, Soc. Histoire Nat. Paris lin., p. 74, 1799. Type (monotype): Turbo terebra Linne, Recent, tropical western
 Pacific.
 Turritella occurs in all marine formations of the Canal Zone and adjoining parts of Panama, except the Chagres sandstone proper. The number of forms therefore is large: 17 species and 3 subspecies. The Gatn formation, which contains 6 species and 2 named minor forms, has the largest number of species. Not more than 4 species, however, were found in the Gatun formation at any one locality.