. Bulletin of the British Museum (Natural History). 75 /:. Figs 74-75 Dyris tricarinata (Boettger). Pcbasian; Puerto Naririo, Colombia; Weeda Colin. 74, GG21527; front, x 20. 75, GG21528; front, x 15. Holotype. GG19792, Late Caenozoic, Pebasian; Pichana, Peru (Hauxwcll Colin, extracted 1982). The following are para- types; all Late Caenozoic, Pcbasian. GG19793, GG21627-9, GG21696-705, Pichana, as above; NYSM 9253, one of seven shells misidentified by Conrad as lsaea ortoni (Gabb) the remaining six are now reidentificd as /). tricarinata (Boettger). GG19799, GG19960, Canama (C. Barrin
. Bulletin of the British Museum (Natural History). 75 /:. Figs 74-75 Dyris tricarinata (Boettger). Pcbasian; Puerto Naririo, Colombia; Weeda Colin. 74, GG21527; front, x 20. 75, GG21528; front, x 15. Holotype. GG19792, Late Caenozoic, Pebasian; Pichana, Peru (Hauxwcll Colin, extracted 1982). The following are para- types; all Late Caenozoic, Pcbasian. GG19793, GG21627-9, GG21696-705, Pichana, as above; NYSM 9253, one of seven shells misidentified by Conrad as lsaea ortoni (Gabb) the remaining six are now reidentificd as /). tricarinata (Boettger). GG19799, GG19960, Canama (C. Barrington Brown Colin. extracted 1982); PIMUZ 491A, unfigured by de Greve (1938); PIMUZ 497C, de Greve, pi. 5, fig. 30 which was copied by Wenz (1939: fig. 1548); PIMUZ 491B, de Greve, pi. 5, fig. 37, all Iquitos. No other records. Name. From Juan Hauxwell's Collection, purchased by the BM in 1870. Distribution. Late Caenozoic, Pebasian only. Upper Amazon basin only. Diagnosis. Like Dyris tricarinata, but much smaller, attain- ing the same number of whorls in half the height and w ith a markedly pagodiform whorl profile. Description. This species has a height of under 3 mm and has about eight whorls. The spiral ribs, which arc first seen on the third whorl, are relatively prominent for its si/e; that at the periphery is normally the strongest and those below it are progressively weaker towards the abapieal suture. There are normally three or four ribs on each w horl but a small propor- tion of Pichana shells and the two Iro n Canama have five or six. Very weak threads can be seen on the base of the bod\ whorl of the Iquitos shells and on some ot those from Pichana On the Iquitos shells, some of the grow th lines are sufficient!) strong to produce the appearance ot eollabral ribbing. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble th
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