GASTROPODS: TROCHIDAE TO TURRITELLIDAE


mined, but on some small shells of the Recent species it is as wide or wider.
 According to Bequaert (1943, p. 24), in his recent monograph of the western Atlantic species of the genus L. angulifera is found, generally on mangroves in brackish inlets, from Florida to Brazil, on the west coast of Africa, and has reached the Pacific coast of Panam'i by transportation through the Panaml Canal. 4This species is recorded from Pleistocene deposits on the Caribbean side of the Canal Zone near Mount Hope (Brown and Pilsbry 1913a, p. 495). It is represented in three of MacDonald's Pleistocene collections from that area (USGS 5849, 5850, 5868) and also in two lots of Pleistocene fossils lie collected at and near the north end of Gatun Locks (USGS 5867, 6038).
 After this report was in proof a small imperfect specimen that seems to be L. angulgifera was found in a collection from strata of middle Miocene age on Rio Banana in southeastern Costa Rica (USGS 5882f) and a large specimen, unequivocally identified as that species, was found in a collection of late Miocene fossils from Swan Cay, in the Bocas del Toro Archipelago, northwestern Panamd (USGS 8305).
 Bequaert (1943, p. 3) assigned L. angulfjere to the subgenus Littoraria.
 Occurrence: Uppermost part of Culebra formation (early Miocene), Gaillard Cut, locality 110.
 Family VITRINELLIDAE
 Studies of Recent vitrinellids have not yet progressed 'far enough to sort the genera of probably diverse affinities that are currently placed in this family. The Gatun formation yielded all the vitrinellids described in the present report.
 Genus Teinostoma H. and A. Adams
 H. and A. Adams, Genera of Recent Mollusca, v. 1, p. 122,
 August, 1853.
 Type (virtual monotype and logotype, A. Adams, Thesaurus
 conchyliorum, pt. 22, p. 259, 1863): Teinostosia politm A.
 Adams, Recent, Santa Elena (presumably Ecuador).
 Pilsbry and McGinty (1945-50, pt. 1, p. 1, 1945) have pointed out that Teiinostoma was virtually monotypic, as T. anomalum C. B. Adams, the only species mentioned other than T. politun, was a nude name.
 No known Caribbean fossil species has the characters of the subgenus Teinostoma s.s.: greatly depressed shell and spoutlike extension of the peristome.
 Subgenus Idioraphe Pilsbry
 Pilsbry, Acad. Nat. Sci. Phila. Proc., v. 73, p. 398, 1922. Type (orthotype): Teinostoma angulatum (Gabb) (Cyclops angulatus Gabb), Miocene, Dominican Republic.
 It has been claimed that the spire of Teinostoma s.s. is concealed by overlap of the body whorl (Woodring, 1928, p. 444) and that it is not concealed (Pilsbry and 413788-57--6


Olsson, 1941, p. 47). As a matter of fact, it has become evident that both statements are justified (Pilsbry and Olsson, 1945-52, p. 38, 1952). The typical form of the type species, known only from Arthur Adams' descriptions and illustrations, reproduced by Pilsbry and Olsson (1945-52, p. 251, pl. 22, fig. 6, 1945; p. 38, pl. 2, figs. 1, la, 1b, 1952), has an exposed spire. A form from the Gulf of California, so similar in essential features to T. politum that it was described as T. politum ultimum (Pilsbry and Olsson, 1945-52, p. 252, pl. 22, figs. 1, la, 1b, 1945), has a concealed spire. In other words, the subgenus Idioraphe, which has a concealed spire, is not as sharply set off as it was once thought to be. Idioraphe also resembles Teinostoma s.s. in having a thick shell, thick callus, and thick enamel. Nevertheless Idioraphe is a useful name for small teinostomes that have a concealed spire, are not strongly depressed, and lack the spoutlike extension of the peristome characteristic of T. politurn.
 Teinostoma (Idioraphe) spermatia Woodring, n. sp.
 Plate 17, figures 19-24, 31-33, 37-39
?Teinostoma cf. carinatum d'Orb., Toula, K. k. Geol. Reichsanstalt Jahrb., Band 61, p. 497, pl. 31, fig. 10, 1911 (Miocene, Canal Zone).
 Small, thick-shelled, depressed but somewhat domeshaped. Periphery bluntly angular on early part of body whorl, narrowly rounded on later part. Tip of spire exposed, remainder concealed by overlap of body whorl. Entire spire concealed by enamel on very large specimens. Umbilical and parietal callus thick and completely coalesced.
 Height 0.7 mm, diameter 1.8 mm (type); height 1.1 mm, diameter 2.6 mm (large form, figured).
 Type: USNM 561312; paratypes, Stanford Univ.
 Type locality: 147b (USGS 6033c, Panama Railroad, about 3,500 feet (1,065 m) southeast of Gatun railroad station, Canal Zone), middle part of Gatun formation.
 Teinostoma spermatia is the most widespread teinostome in the middle part of the Gatun formation and is particularly abundant at the type locality, where several hundred specimens were collected. It is represented, however, by only one specimen from the upper part of the formation, and none was found in the lower part.
 Immature shells (pl. 17, figs. 22-24) are more nearly circular than mature shells. Furthermore the outer lip of immature shells ascends almost to the tip of the spire and therefore has a different outline from that of mature shells. Three specimens from the type locality, one of which is illustrated (pl. 17, figs. 19-21), show faint to fairly strong microscopically punctate spiral striae. This sculpture is doubtless a normal character, but is ordinarily concealed by enamel. The three


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