GEOLOGY AND PALEONTOLOGY OF CANAL ZONE


in the collections from localities 162 and 162a. As shown by the illustrations, the sculpture is variable. On some specimens the axial waves are so strong that the sculpture has a cerithid appearance; on a few they are absent or practically absent. The strong constriction of the posterior part of the whorls and the strong minor spirals are characteristic features. In whorl profile T. gatunensis rhytodes closely resembles T. gatunensis willistoni Hodson (1926, p. 25, pl. 18, figs. 2-4), which, however, has strongly differentiated primary and secondary spirals on late whorls. Axial waves were cited as the characteristic feature of T. gatunensis taratarana Hodson (1926, p. 25, pl. 18, figs. 5, 7). The posterior part of the whorls of that form are not strongly constricted. The presence or absence of axial waves evidently is a variable character in different forms of T. gatunensis, including the typical form. T. gatunensis willistoni and T. gatunensis taratarana appear to be varieties of T. gatunensis. They are found together at some localities in Miocene strata in Falc6n, Venezuela, and at a few localities are recorded in association with T. gatunensis lovelana, which, as indicated by the synonomy citation under T. gatunensis, is considered the typical form.
 The typical form of Turritella subannulata Heilprin (1887, p. 89, pl. 8, fig. 17), a Pliocene species from Florida, has cerithid axial sculpture, two primary spirals on intermediate and late whorls, and a growth line similar to that of T. gatunensis. The development of the sculpture, however, indicates that it is not closely allied to T. gatunensis.
 "Turritella gatunensis" tarataranoides Haas (1942, p. 315, figs. 3, 4), and also "Crepitacella" altispira Haas (idem, p. 315, figs. 5, 6) and "Crepitacella' n. sp. indet. aff. "C." altispira Haas (idem, p. 316), are fresh-water snails, as the editor of the Journal of Paleontology was informed when Haas' manuscript and illustrations were received. The type material of these species is so poorly preserved that their affinities are uncertain, but the "Turritella" seems to beaPachychilus. Not only is the type material poorly preserved, these species also were collected at an unknown Costa Rican locality (Idem, p. 310). Despite these deficiencies, they were given an unqualified middle Miocene age. Specimens of these fresh-water snails, collected in 1910 in a tunnel at Brasil (in the Meseta Central west of San JosS), are in the collections of the U. S. National Museum. They were presented to W. H. Dall by Don Anastasio Alfaro, Director of the Museo Nacional at San JosS, during a visit to Washington.
 Occurrence: Middle part of Gatun formation (middle Miocene), localities 162, 162a.


 Subgenus?
 Turritella cf. T. berjadinensis cocoditana Hodson
 A whorl fragment from the Culebra formation has a strong carina-forming spiral at the anterior fourth, two primary spirals near the middle, two weaker spirals between the carina and the anterior suture, and closely spaced fine minor spirals over the entire whorl.
 Though its middle spirals are of subequal strength, this fragment is comparable to the Miocene Venezuelan Turritella berjadinensis cocoditana (Hodson, 1926, p. 29, pl. 19, fig. 5, pl. 20, figs. 3, 7, 10).
 Occurrence: Culebra formation (early Miocene), Gaillard Cut, locality 115b.
 Subgenus? (Merriam's T. broderipiana stock)
 Turritella mimetes Brown and Pilsbry Plate 22, figures 6-9
Turritella mimetes Brown and Pilsbry, Acad. Nat. Sci. Phila,
 Proc., v. 63, p. 357, pl. 27, fig. 1, 1911 (Miocene, Canal Zone)..
 Olsson, Bull. Am. Paleontology, v. 9, no. 39, p. 149, pl. 14,
 fig. 5, 1922 (Miocene, Canal Zone).
Turritella (Haustator) aff. T. hanleyana Reeve, Toula, K. k. Geol.
 Reichsanstalt Jahrb., Band 61, p. 498, pl. 30, fig. 6, 1911.
 (Miocene, Canal Zone).
?Turritella mimeles Brown and Pilsbry, Anderson, Calif. Acad.,
 Sci. Proc., 4th ser., v. 18, no. 4, p. 120, 1929 (Miocene,, Colombia; not described, possibly T. lloydsmithi Pilsbry andi
 Brown).
Not Turritella cf. T. iaimetes Brown and Pilsbry, Merriam, Calif:
 Univ. Dept. Geol. Sci. Bull., v. 26, no. 1, pl. 38, fig. 7, 1941
 (Miocene, Colombia;= T. lloydsmithi Pilsbry and Brown).
 Moderately large, slender. Whorl profile flat or slightly concave. Late intermediate and late whorls generally loosely clasping, producing a weak basal carina. Protoconch cylindrical, of 1% inflated whorls. Early sculptured whorls attenuated, strongly inflated. A middle spiral, forming a weak carina, and minor spirals appear on first sculptured whorl. Middle spiral decreasing in strength on next whorl and lost among minor spirals covering entire whorl. Second and succeeding sculptured whorls therefore not medically carinate. On some specimens a median spiral again attains slight prominence on sixth or seventh sculptured whorl. Late whorls sculptured with spirals roughly representing three ranks, the third rank being microscopic. Base sculptured with numerous spirals. Growth-line sinus wide and shallow; growth-line angle wide. Interior of late whorls smooth or bearing narrow spiral ridges.
 Height (incomplete) 73 mm. diameter 17.5 mm (largest figured specimen).
 Type: Acad. Nat. Sci. Phila. 1734.


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