Microgloma macaron Benaim & Absalão 2011

Shell minute, ovate, H/L ratio about 0.81 (n 38, min 0.75, max 0.92), W/H ratio about 0.84 (n 14, min 0.77, max 0.87), glossy, translucent, robust for its size, equilateral; umbones prominent, large, posterior to midline, orthogyrous. Antero–dorsal margin straight, oblique; anterior margin rounded, extended. Antero–ventral margin, postero–ventral margin shorter and rising up to the short posterior end; posterior margin slightly truncated, forming a small shoulder. Entire shell margin thickened and covered by an extension of the periostracum, resembling a macaroon in ventral view (Figs 21–22). Surface with commarginal growth lines. Hinge plate with 5–7 anterior and 4–5 posterior teeth, interrupted by a large, rectangular and shallow resilifer. Width of both anterior and posterior row of teeth occupies about 70% of width of hinge plate, which is thick for its size (whp/H approximately Campos Basin, #54, 12/12/2002 0.14). Posterior part of the hinge plate shorter than anterior one. Prodissoconch surface nacreous, with one subtle radial striae (Fig 20), and length approximately 244 µm. Maximum adult shell length 1.20 mm. Measurements of the type material. * Width = width of a single valve. Microgloma macaron sp. n. Length Height Width* MNRJ 19.112 1.20 1.00 0.36 IBUFRJ 15.297 1.11 0.87 0,31 IBUFRJ 15.297 1.11 0.89 0.36 IBUFRJ 15.297 1.11 0.91 0.36 IBUFRJ 15.297 1.11 0.84 0.33 IBUFRJ 15.297 1.11 0.89 0.36 IBUFRJ 15.297 1.11 0.89 0.36 IBUFRJ 15.297 1.16 0.93 0.38 IBUFRJ 15.297 1.11 0.91 0.33 IBUFRJ 15.297 1.13 0.82 0.31 IBUFRJ 15.297 1.13 0.89 0.33 MZSP 99.979 1.11 0.87 0.33 MZSP 99.979 1.13 1.04 0.36 MZSP 99.979 1.16 0.93 0.38 MZSP 99.979 1.11 0.91 0.31 USNM 1156943 1.11 0.89 0.36 USNM 1156943 1.11 0.89 0.36 USNM 1156943 1.13 0.91 0.36 USNM 1156943 1.13 0.89 0.38 USNM 1156943 1.13 0.91 0.33 USNM 1156943 1.11 0.89 0.36 MNHN 24596 1.11 0.91 0.33 MNHN 24596 1.18 0.93 0.38 MNHN 24596 1.11 0.91 0.36 MNHN 24596 1.11 0.89 0.38 MNHN 24596 1.11 0.91 0.36 MNHN 24596 1.04 0.87 0.38