Basic anatomy of species of Triphoridae (Gastropoda, Triphoroidea) from Brazil Fernandes, Maurício Romulo Pimenta, Alexandre Dias European Journal of Taxonomy 2019 2019-04-17 517 1 60 73DQN (C. B. Adams, 1850) C. B. Adams 1850 [565,1022,972,1000] Gastropoda Triphoridae Metaxia Animalia 9 10 Mollusca species rugulosa   Figs 2B, 4    Material examined   BAHAMAS• [2, 1 d] specs; Abaco;  0.2 mdepth;  11 Jul. 1994; C. Redfernleg.; BMSM 56034.    Description of basic anatomy OPERCULUM. Elliptical, thin, semi-transparent, membranous, paucispiral, ~2.25 whorls, nucleus considerably eccentric, dislocated 47% from center towards margin; diameter of operculum exceeds diameter of opercular pouch in 10%. JAW. Wing-shaped; outer side with scales rectangular or rhombus-shaped, some of them covered by micro-pores up to 330 nmin diameter; rectangular scales 13.4–25.2 µmlong, 5.0– 11.1 µmwide, ratio length/width 2.3–3.1, rhombus-shaped scales 19.8–22.2 µmlong, 6.8–9.4 µmwide, ratio length/ width 2.3–3.2. RADULA. Formula 3-1-1-1-3; central tooth with four main cusps, triangular and curved (claw-like), outer cusps slightly broader and occupying an upper position in relation to inner ones, in addition to a fifth, median and thin cusp up to 60% the length of remaining cusps; lateral teeth with four cusps, of which 1, 3 and 4 are claw-like and cusp 2 is vestigial or very reduced (up to 56% the length of remaining cusps); M1 with three to four cusps, cusps 1 and 4 slightly broader, cusp 2 often considerably reduced but even reaching the same length of remaining cusps; M2 with three to four small cusps; M3 very reduced, usually with three small cusps; central tooth 7.7–8.7 µmwide, lateral teeth 6.7–7.4 µmwide, M1 5.4–7.6 µmwide, M2 4.0–5.0 µm wide, developed M3 2.1–3.0 µm wide.    Remarks The white color of the soft parts of  M. rugulosawas illustrated by Redfern (2013), and the specimen herein figured was poorly preserved inside the shell, giving a false aspect of cream color to the external morphology ( Fig. 4A–B). The operculum of  M. rugulosaresembles that of  M. exaltata, despite   Fig. 4.  Metaxia rugulosa(C.B. Adams, 1850). A–I. BMSM 56034. A–B. External morphology. C–D. Jaw, outer side. E–I. Radula. Scale bars: A–B = 1 mm; C = 20 µm; D = 2 µm; E–G = 10 µm; H–I = 5 µm. the former showing a shorter whorl expansion ( Fig. 4B) instead of the wide whorl expansion of the latter and its consequent more eccentric nucleus ( Marshall 1977).   Metaxia rugulosahas a paucispiral protoconch with a few spiral threads in the embryonic whorl, and has a radula ( Fig. 4E–I) with tooth morphology similar to that of species with a multispiral protoconch with several spiral threads in the embryonic whorl, e.g.,  M. excelsa,  M. exaltataand the typespecies  M. metaxa. A remarkable aspect of the radula of  M. rugulosais the reduced number of marginal teeth (three), which is followed by  M. excelsa(four),  M. metaxaand Nützel’s  Metaxiasp. 2 (five), Nützel’s  Metaxiasp. 1 (six) and  M. exaltata(nine or ten). The increment of teeth at the margins of the radular ribbon was indicated by Marshall (1977)for  M. exaltata, and could be the reason for the deviation of this genus from the taenioglossate radula (with two marginal teeth) typical of Cerithiopsidae. 2236664066 [189,1303,1119,1147] 1994-07-11 BMSM C. Redfern Bahamas 2 Abaco 9 10 BMSM 56034 1 South Abaco