GASTROPODS: TROCHIDAE TO TURRITELLIDAE


One or more of the numerous generic and subgeneric names proposed for European, Australian, and Neozelanic rissoids may possibly be suitable for "Alvania' aff. "A." epulata.
 Nevill's designation for the type of Alvania-"type A. cimex Lin. [as Alv. curopaea Risso]"-appears to be the earliest valid designation. It has the same effect as numerous designations of Turbo cimex Linn6 and the much later designation of Alvania freminvillea Risso, also a synonym of Turbo cimex (Gordon, 1939, p. 29).
 Occurrence: Lower and upper parts of Gatun formation (middle Miocene). Lower part, locality 136a (1 immature). Upper part, eastern area locality 173 (1 mature, protoconch crushed during examination).

 Family RISSOINIDAE
 Genus Rissoina d'Orbigny
 d'Orbigny, Voyage dans l'Amnrique M6ridionale, t. 5 (Mollusques), p. 395, 1840.
 Type (monotype): Rissoina inca d'Orbigny, Recent, Perd and
 Chile.
 Subgenus Zebinella Mrch
 Mtrch, Malakozool. Blatter, Band 23, p. 47, 1876. Type (logotype, von Martens, Zool. Record, 1876, p. 30, 1877):
 Rissoina decussala (Montagu) (Helix decussata Montagu), Recent, West Indies and Florida (described as a British
 species).
 Rissoina (Zebinella?) species
 A poorly preserved altered shell from the Culebra formation is assigned to Rissoina on the basis of outline and sculpture. The outer lip and aperture are not preserved. The sculpture, consisting of narrow axial ribs and fine spiral threads between the ribs, suggests the subgenus Zebinella.
 Occurrence: Culebra formation (early Miocene), Gaillard Cut, locality 99b.
 Subgenus Phosinella Mdrch
M6rch, Malakozool. Bitter, Band 23, p. 51, 1876. Type (logotype, Nevill, Hand list of Mollusca in the Indian
 museum, pt. 2, p. 73, 83, 1885): Rissoina pulchra (C. B.
 Adams) (Rissoa pulchra C. B. Adams), Recent, West Indies.
 Rissoina (Phosinella) oncera Woodring, n. sp.
 Plate 23, Figure 3
 Small, slender. Protoconeh of 3)( smooth rapidly enlarging whorls, the last half whorl obscurely angulated. Sculpture reticulate; axial ribs slightly wider than spiral threads. Four spirals at beginning of penult, five on later half. Outer lip strongly varicose. Fa-siolelike swelling on base strongly inflated.
 Height 4.3 mm, diameter 1.7 mm (type).
 Type: USNM 561332.
 Type locality: 177c (USGS 5855, west side of Panama Railroad, opposite Mount Hope cemetery, Canal Zone), upper part of Gatun formation.


77


 The type (and only) specimen of this species was collected from the upper part of the Gatun formation at Mount Hope. It is closely allied to R. guppyi Cossmann (Woodring, 1928, p. 366, pl. 28, fig. 10), which occurs in the Bowden formation of Jamaica and in the Cercado and Gurabo formations of the Dominican Republic, but has a more widely expanding protoconch, slightly narrower spirals on the early whorls, more inflated fasciolelike swelling, and wider space between the swelling and the lowest spiral. The Recent West Indian and Florida species identified by Dall (1890-1903, pt. 2, p. 343, 1892) as R. cancellata Philippi has a smaller protoconcb, coarser sculpture, and less inflated fasciolelike swelling.
 Occurrence: Upper part of Gatoin formation (middle Miocene), eastern area, locality 177c.

 Family XENOPHORIDAE
 Genus Xenophora Fischer von Waldheim
 Fischer (von Waldheims(, Mus6um-Demidoff, t. 3, p. 213, 1807. Type (logotype, Harris, Catalogue of Tertiary Mollusca in the
 British Museum; pt. 1, Australasian, p. 253, 1897): Xenophora laevigata Fischer [von Waldheim] ("Trochus conchyliophorus Gmel., Bose, Born") = Trochus conchyliophorus Born, Recent,
 West Indies.
 Unidentified species of Xenophora are represented by two molds from the Gatuncillo formation and an incomplete mold from the Culebra formation.

 Xenophora delecta (Guppy)
 Plate 22, figures 1, 2,4
 Phorus agglutinans (Lamarck), Gabb, Am. Philos. Soc. Trans.,
 n. ser., v. 15, p. 241, 1873 (Miocene, Dominican Republic). Phorus delecta Guppy, Geol. Soc. London Quart. Jour., v. 32, p.
 529, pl. 28, fig. 10, 1876 (Miocene, Dominican Republic). Xenophora delecta (Guppy), Maury, Bull. Am. Paleontology, v.
 5, no. 29, p. 134, pl. 23, figs. 8, 9, 1917 (Miocene, Dominican Republic). Pilsbry, 1922, Acad. Nat. Sci. Phila. Proc., v. 73, p. 385, pl. 32, figs. 7, 8, 1922 ("dilecta" by error; Mliocene, Dominican Republic). Woodring, Carnegie Inst. Washington
 Pub. 385, p. 376, pl. 30, figs. 3, 4, 1928 (Miocene, Jamaica). Xenophora conchyliophora (Born), Maury, Bull. Am. Paleontology, v. 5, no. 29, p. 133, pl. 23, fig. 7, 1917 (Miocene, Dominican
 Republic).
 Xenophora aff. trochiforom is (Born), Rutsch, Schweizer. Palaeont.
 Gesell. Abh., Band 54, no. 3, p. 48, pl. 2, figs. 2, 3, 1934
 (Miocene, Venezuela).
 Moderately large, widely umbilicate. Spire low, periphery somewhat extended. Sculpture above periphery, between agglutinated shells and shell fragments, consisting of strongly protractive irregularly rippled threads. Base sculptured with niore uniform rippled arcuate threads parallel to columeller lip, which is broken back.
 Height 25 nim, diameter (incomplete) 46 mm (figured specimen).