GASTROPODS: TROCHIDAE TO TURRITELLIDAE


 P. coensis (Dall) (Mansfield, 1930, p. 124, pl. 17, fig. 8), which occurs in deposits of late Miocene age in western Florida, and P. robustus Gardner (1926-47, p. 550, pl. 59, figs. 5, 14, 1947), a middle Miocene form, are the representatives of P. stanislas-meanieri in the Miocene of Florida. P. coensis is smaller than the Caribbean ,species. It has a more distinct notch between the umbilical callus lobe and parietal callus, thicker parietal callus, and the transverse groove on the parietal callus persists to a later stage than on Gatun fossils. P. robustus, which perhaps is to be considered a large highspired subspecies of P. coensis, closely resembles highspired Gatun shells, but has a thicker parietal callus.
 P. coensis is the type of the subgenus Dallitesta Mansfield (1930, pp. 124, 125), which was proposed without any discussion of differentiating characters. Perhaps it was proposed because of the distinct spiral lineation. Should the genus Polinices be subdivided into subgenera, Dallitesta would be available for species that have a narrow umbilicus, virtually no umbilical rib, narrow umbilical callus lobe, and distinct spiral lineation. There are, however, gradations from a strong umbilical rib, like that P. canalizonalis, to virtually none; and many species, including P. brunneus, the type of the genus, have more or less distinct spiral lineation.
 Occurrence: Lower, middle, and upper parts of Gatun formation (middle and late Miocene). Lower part, localities 136, 136a, 137, 138, 138a. Middle part, eastern area, localities 140, 146 (immature, identification doubtful), 147b (immature, identification doubtful), 147g (immature, identification doubtful), 147h (immature, identification doubtful), 155, 155c (incomplete, immature, identification doubtful), 157, 159a; western area, localities 161, 161c. Upper part, eastern area, localities 171, 173 (incomplete, identification doubtful), 177b; western area, localities 182, 182a, 183, 185 (im,nature, identification doubtful). Middle Miocene, Cost. Rica. Gurabo(?) formation (middle Miocene), Dominican Republic. Miocene, Bolivar, Colombia. Miocene, Falc6n, Venezuela. Springvale formation (late Miocene), Trinidad.
 Genus Neverita Risso
Risso, Histoire naturelle des principales productions de l'Europe
 m6ridionale, v. 4, p. 149, 1826.
Type (monotype): Neverita josephinia Risso, Recent, Mediterranean Sea.
 The Gatuncillo and Culebra formations, Emperador limestone member of the Culebra formation, and the La Boca marine member of the Panama' formation yielded molds of low-spired naticids identified as Neverita? sp. A large low-spired naticid from the marine member of the Bohio(?) formation near Palenquilla Point (diameter 39 millimeters), the umbilicus of which is not exposed, also is identified as Neverita? sp.


91


 Subgenus Glossaulax Pilsbry
 Pilsbry, Nautilus, v. 42, p. 113, 1929. Type (orthotype): Neverita reclusiana (Deshayes) (Natica
 reclusiana Deshayes), Recent, southern California to Gulf of
 California.
 The subgenus Glossaulax embraces neverites that have a groove on the umbilical callus, dividing it into anterior and posterior lobes. The groove of the type species is located on the anterior part of the callus.
 Glossalax is widely distributed on both sides of the northern Pacific and is represented in the Eocene of western North America by a typical species, N. seca Gabb, which Stewart (1927, p. 325) suggested may be treated better as a subspecies of N. reclusiana. This subgenus formerly had a more extensive distribution. It is represented in the Eocene of southeastern United States by N. limula (Conrad) (Palmer, 1937, p. 125, pl. 13, figs. 13, 14, 16, 19-22, pl. 80, figs. 13, 16), in the Eocene of the Caribbean region by N. bolivarensis Clark, and in the Eocene or Oligocene of Peru by N. subreclusiana (Olsson). These early Tertiary species are hardly typical, as the umbilical callus groove is not consistently present. Typical species, however, mentioned under N. reclusiana xena, are found in the Miocene of Florida and the Caribbean region.
Neverita (Glossaulax) bolivarensis tapina Woodring, n. subsp.
 Plate 15, figures 7, 8, 11
 Of medium size, depressed, conical. Umbilical callus partly filling umbilicus, the wide unfilled space decreasing in width toward parietal callus, but extending to junction of umbilical and parietal callus. Parietal callus set off from umbilical callus by a faint groove. Posterior part of umbilical callus bearing a faint groove. Umbilical wall faintly striate.
 Height 14.5 mm, diameter 19 mm (type). Height 16.5 mm, diameter 26.5 mm (largest specimen).
 Type: USNM 561354. Paratype, USNM 561442.
 Type locality: 40d (USGS 6028a, Gatun Lake area, lower bed at Vamos Vamos, off Palenquilla Point, Canal Zone, now submerged), marine member of Bohio(?) formation.
 Though Neverita bolivarensis tapina is represented by 12 specimens from the marine member of the Bohio(?) formation, only a few show the callus features. The callus is completely exposed on the type and paratype, both of which have a relatively wide unfilled umbilical space, a faint groove between the umbilical and parietal callus, and a faint groove on the posterior part of the umbilical callus. The groove on the umbilical callus of the type probably is modified by an artificial crack. The paratype has a shallow groove that disappears before reaching the umbihical border. Enough of the umbilical callus is exposed on two other specimens to