. Bulletins of American paleontology. Miocene Mollusca Venezuela : Jung 517 The largest specimen (H 13704) (siphonal canal broken, height 68 mm.) has five whorls in all. Most of the other specimens, from the smallest ones over any intermediate size to the largest ones, have 4l/2 to 5 volutions. Therefore they must be adult or nearly so (outer lip mostly broken) . The number of nuclear whorls is not constant. Text-figure 3 shows the manner in which the nuclear whorls have been counted. Fourteen (of the 23 well-preserved) protoconchs have 2% volu- tions, five have 2l/z volutions, and four have o
. Bulletins of American paleontology. Miocene Mollusca Venezuela : Jung 517 The largest specimen (H 13704) (siphonal canal broken, height 68 mm.) has five whorls in all. Most of the other specimens, from the smallest ones over any intermediate size to the largest ones, have 4l/2 to 5 volutions. Therefore they must be adult or nearly so (outer lip mostly broken) . The number of nuclear whorls is not constant. Text-figure 3 shows the manner in which the nuclear whorls have been counted. Fourteen (of the 23 well-preserved) protoconchs have 2% volu- tions, five have 2l/z volutions, and four have only two. The speci- mens from Springvale described by Rutsch (1942, p. 144) show only two volutions or even somewhat less than two. Woodring (1959, p. 211) indicates "about 1'/>" for specimens from the Panama Canal Zone. Smith (1907, p. 217) stated that the number of volutions decreases from older times to Recent. A Recent speci- men of F. ventricosa (G. B. Sowerby I) at hand has 1 l/2 volutions. Summarizing the above remarks I believe that there is an astonish- ing variability in this species. This feature leads one to the supposi- tion that F. carbasea micronernatica (Brown and Pilsbry) = Pyrula peruviana Spieker (fide Woodring 1959, p. 212) might be synony- mous with F. earbasea F. carbasea micronernatica essentially is a smaller subspecies of F. carbasea Its nuclear whorls are not known. It is recorded from the early Miocene and possibly Oligocene of the Panama Canal Zone. However, only an examina- tion of the type material cotdd bring one nearer to the answer of this Text-fig. 3. Scheme showing how volutions are counted, (after Ehrmann 1933, p. 21, fig. 12). a: starting point, b: one volution completed. A cast of a paratype of F. colombiana Anderson at hand strongly suggests its synonymy with F. carbasea Comparisons. —F. carriacouensis Trechmann (1935, p. 543, pi. 21, fig. 16) from the Miocene of Carriacou is more contracted.
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