Geology and Paleontology of Canal Zone and Adjoining ... - USGS

GASTROPODS: EULIMIDAE, MARGINELLIDAE TO HELMINTHOGLYPTIDAE 337
ing after first third of first post-protoconch whorl.
According to collections in the U.S. National Museum,
her first type is shown by specimens from the Cercado
formation and her second type by specimens from the
Gurabo formation. 0. epistomifera dariena shows the
first type, although some variation in the size of the
protoconch is apparent. The contrast in the two types
of protoconch is shown in illustrations of a specimen
from the Gurabo formation and one from the Gatun
formation (Jung, 1965, pi. 75, figs. 3, 4, respectively).
The chief difference between C. epistomifera dariena
and the nominate subspecies lies in the greater range
of variation, in outline and sculpture, of the Canal
Zone subspecies.
The subgenus Cancellaria s.s. is an appropriate as­
signment for C. epistomifera, although that species
formerly (Woodring, 1928, p. 221) was referred to the
subgenus later named SivetieUa by Wenz (1943, p.
1356; type (orthotype: Cancellaris similis Sowerby, liv­
ing, west Africa).
Occurrence: Lower, middle, and upper parts of
Gatun formation (middle Miocene). Lower part, locali­
ties 136, 136a, 137, 138, 138a, 138b, 138c, 138d, 138e,
138f. Middle part, eastern area, localities 139c, 139e,
139f, 140, 147 (identification doubtful), 147f (identi­
fication doubtful), 154 (identification doubtful), 155,
155a, 155b, 155c, 157, 159, 159b, 159d; western area,
localities 161, 161a, 161c, 170 (identification doubtful).
Upper part, eastern area, localities 172, 175, 176, 176a,
177 (identification doubtful), 177b, 178. Middle Mio­
cene, Costa Rica, Colombia, Darien area (USGS 8477),
Chiriqui area (USGS 7955). Limon formation (Late
Miocene), Bocas del Toro area, Panama. Miocene,
Ecuador. Chagres sandstone (late Miocene), locality
208 (C. aff. C. epistomifera dariena).
Cancellaria (Cancellaria) epistomifera lipara Woodring,
n. subsp.
Plate 52, figures 7, 8
Smaller than Cancellaria epistomifera dariena, in­
flated, spire somewhat turreted. Axial ribs closely
spaced, 25 to 33 on penult whorl. Secondary spiral
threads absent. Terminal varix and a nearby earlier
varix subdued, or both absent. Notch on basal part of
outer lip very shallow or absent.
Height 28 mm, diameter 17.5 mm (type). Estimated
restored height 30 mm, diameter 18 mm (largest speci­
men).
Type :USNM 645719.
Type locality: 183 (USGS 8487, Caribbean coast
east of Eio San Miguel [Eio Miguel], station 4 plus 40
feet (12 meters), Panama), upper part of Gatun for­
mation.
Cancellaria epistomifera lipara is represented by 17
specimens from the type locality and one from locality
182a. Both localities are in the upper part of the Gatun
formation in the western area. In marked contrast to
the diversity shown by C. epistomifera dariena, these
18 cancellarids are fairly uniform. The combination of
relatively small size, closely spaced axial ribs, absence
of secondary spiral threads, subdued varices (or their
absence), and very shallow notch (or its absence) on
the outer lip distinguish them from G. epistomifera
dariena and C. epistomifera epistoinifera. Despite their
small size, the largest specimens of C. epistomifera
lipara, like the small form of 0. epistomifera epistomi­
fera in the Gurabo formation of the Dominican Re­
public, have a swollen siphonal fasciole and heavy
columellar folds, indicating that they are mature.
The Limon formation, of late Miocene age, on Cayo
de Toro, in the Bocas del Toro area of northwestern
Panama (USGS 8326), yielded one specimen of C.
epistomifera lipara (height 31 mm), associated with
four of C. epistomifera dariena.
The axial ribs of an immature shell (height 16.3
mm) in the large collection from the lower part of the
Gatun formation at locality 183c are even more closely
spaced than those of C. epistomifera lipara, and so are
the spiral cords. This fossil is doubtfully identified as
an aberrant form of C. epistomifera dariena.
Occurrence: Upper part of Gatun formation, west­
ern area (middle Miocene), localities 182a, 183. Limon
formation (late Miocene), Bocas del Toro area,
Panama.
Cancellaria (Cancellaria) apimela Woodring, n. sp.
Plate 52, figures 5, 6
Small, slender, spire distinctly turreted. Protoconch
missing, early sculptured whorls corroded. Earliest
preserved sculpture consisting of axial ribs and eight
low, flat spiral cords. Axial ribs strong and widely
spaced on last two whorls. Penult whorl bearing 12 or
13 axial ribs and nine low, flat spiral cords, separated
by narrow grooves. Spiral sculpture subdued on main
part of body whorl. One or two axial ribs on last two
whorls wider and lower than others.
Height 22.6 mm, diameter 13 mm (type).
Type:USNM 645720.
Type locality: 182a (USGS 8488, Caribbean coast
east of San Miguel [Rio Miguel] station 25 plus 400'
feet (120 meters), Panama, upper part of Gatun
formation.
This distinctive species is based on two specimens
from the upper part of the Gatun formation in the
western area. Part of both shells the part exposed
when they were collected is corroded.