. Bulletin of the British Museum (Natural History). . Figs 87-91 Dyris semituberculata sp. nov. Late Caenozoic; km upstream from La Tagua, Colombia; Weeda Colin. 87, holotype. GG19853; front, x 15. 88-91, paratypes. 88, GG21623; a, front, x ; b, early spire whorls, x 50. 89, GG21621; front, x 20. 90, GG 19854; a. front, x 20; b, penultimate whorl, x 40. 91, GG21625; front, showing undamaged aperture, x 10. another quite strong rib lies between the lower carina and the lower suture. A further carina lies at the lower suture; it is only partly exposed, except on the body whorl
. Bulletin of the British Museum (Natural History). . Figs 87-91 Dyris semituberculata sp. nov. Late Caenozoic; km upstream from La Tagua, Colombia; Weeda Colin. 87, holotype. GG19853; front, x 15. 88-91, paratypes. 88, GG21623; a, front, x ; b, early spire whorls, x 50. 89, GG21621; front, x 20. 90, GG 19854; a. front, x 20; b, penultimate whorl, x 40. 91, GG21625; front, showing undamaged aperture, x 10. another quite strong rib lies between the lower carina and the lower suture. A further carina lies at the lower suture; it is only partly exposed, except on the body whorl of specimens with detached peristomes, when it is revealed to be extremely strong, forming a flange which separates the side from the base of the whorl. The c. 20 collabral nodes on the early whorls reduce to 14-16 collabral ribs on the later whorls. In section, these ribs are of an angular, zigzag pattern, except near both sutures where they broaden into low scmiangular folds. As far as can be seen, the ribbing runs parallel to the growth lines, and is therefore collabral. The growth lines arc weak, except on the base. In the single studied specimen, the sculpture is reduced in strength on the last whorl as it approaches the aperture. The base of the whorl is convex and lacks ribbing. The peristome is detached in some, but not all. Dimensions. In mm. h br h/br sa PIMUZ 423, holotype (de Greve 1938: pi. 2, figs 32-34). () (30°-22°) PIMUZ 418D (pi. 3. fig. 5). (18°) PIMUZ 430 (pi. 3, fig. 7). (34°) PIMUZ (studied herein). Note. Except for the uti numbered specimen studied herein, the figures are taken either from de (irc\c's ( ll'3S) text or from his plates; the latter are given in brackets I he discrepancies are particularly great in the case ol the holotype. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these il
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