. Bulletin of the British Museum (Natural History). . Figs 83-85 Dyris hauxwelli sp. nov. Pebasian; Iquitos, Peru; originally identified by de Greve (1938) as Dyris gracilis Conrad. 83, PIMUZ 491a; front, x 30. 84, PIMUZ 491b, figured by de Greve (1938: pi. 5, fig. 37); front, x 30. 85, PIMUZ 497c; a, front, x 30; b, apical whorls, x 75, figured by de Greve (1938: pi. 5, fig. 30). placed in the synonymy of P. cebada (Anderson, 1928): see p. 311) are paratypes. Other records. 'Also at many localities near La Cira' (Pilsbry & Olsson 1935: 9). Distribution. Only known from the La Ci
. Bulletin of the British Museum (Natural History). . Figs 83-85 Dyris hauxwelli sp. nov. Pebasian; Iquitos, Peru; originally identified by de Greve (1938) as Dyris gracilis Conrad. 83, PIMUZ 491a; front, x 30. 84, PIMUZ 491b, figured by de Greve (1938: pi. 5, fig. 37); front, x 30. 85, PIMUZ 497c; a, front, x 30; b, apical whorls, x 75, figured by de Greve (1938: pi. 5, fig. 30). placed in the synonymy of P. cebada (Anderson, 1928): see p. 311) are paratypes. Other records. 'Also at many localities near La Cira' (Pilsbry & Olsson 1935: 9). Distribution. Only known from the La Cira Formation, as above. This formation was dated as either late Oligocene or early Miocene by Pilsbry & Olsson (1935), but is here regarded as Miocene. Diagnosis. Dyris with spiral ribs increasing from two to five with growth and confined to the lower half of whorl; whorl profile biconvex to weakly carinate at mid whorl-height. Description. All the specimens are damaged: neither the apical whorls nor the aperture are properly known and the ribbing can only be examined on small, isolated, areas of shell surface. The spiral ribs, which are absent from the upper part of the whorl, are weak and increase in number from two or three on early whorls to five on the last whorl. On early whorls, the uppermost rib is just above the periphery but on later whorls it descends as low as the periphery. The whorl profile is usually evenly biconvex, though exceptionally the topmost rib forms a weak carina. Dimensions. In mm. h br hap h/br sa Holotype, GG19792, Pichana. 21° GG21627, Pichana. 22° GG21628, Pichana. 32° GG21629, Pichana. 32° GG19799, Canama. 24° PIMUZ 497C, Iquitos. 18° PIMUZ 491B, Iquitos. 20° PIMUZ 491A, Iquitos. 18° Remarks. The differences between similar species of Dyris with smooth ramps are discussed under D. tricarinata (Boettger),
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