Gergovia petiti De & De, 2007, n. sp.

Gergovia petiti n. sp.

(Figures 12–17)

Type material: Holotype, MZUSP 77067 [Lt 3.7 mm, Wt 2 mm]; Paratype 1, MZUSP 77068, along the state of Alagoas, Brazil, D­31, 10 °06’35’’S, 35°46’41’’W, 720 m, muddy bottom, 16.xii.2001; Paratype 2, MNRJ 10572, along the state of Alagoas, Brazil, D­31, 10 °06’35’’S, 35°46’41’’W, 720 m, muddy bottom, 16.xii.2001; Paratype 3, MNRJ 10573, along the state of Alagoas, Brazil, D­31, 10 °06’35’’S, 35°46’41’’W, 720 m, muddy bottom, 16.xii.2001; Paratype 4, LMUFRPE 0 0 1, along the Fernando de Noronha Archipelago, state of Pernambuco, Brazil, D­14, 03°54,9’00’’S, 32°37,8’00’’W, 380 m, muddy bottom, 12.x.2001; Paratype 5, MORG 50.655, along the state of Rio Grande do Norte, Brazil, D­26, 06 °14’04’’S, 34°52’33’’W, 510 m, muddy bottom, 26.xi.2001; Paratype 6, MORG 50.656, along the Fernando de Noronha Archipelago, state of Pernambuco, Brazil, D­14, 03°54,9’00’’S, 32°37,8’00’’W, 380 m, muddy bottom, 12.x.2001; Paratype 7, LMUFRPE 0 0 2, along the state of Pernambuco, Brazil, D­1, 06°25,6’00’’S, 34°43,9,’00’’W, 425 m, muddy bottom, 29.viii.1999.

Additional material: 3 specimens, MHNC 64506, along the state of Rio Grande do Norte, Brazil, D­27, 06 °14’24’’S, 34°52’06’’W, 500 m, muddy bottom, 16.xi.2001; 3 specimens, LMUFRPE 0 0 3, along the state of Rio Grande do Norte, Brazil, D­29, 06 °13’22’’S, 34°52’20’’W, 223 m, muddy bottom, 16.xii.2001; 2 specimens, LMUFRPE 0 0 4, along the state of Ceará, Brazil, D­18, 02 °05’19’’S, 41°05’01’’W, 390 m, muddy bottom, 30.x.2001; 1 specimen, LMUFRPE 0 0 5, along the state of Alagoas, Brazil, D­31, 10 °06’35’’S, 35°46’41’’W, 720 m, muddy bottom, 16.xii.2001; 2 specimens, LMUFRPE 0 0 6, along the state of Rio Grande do Norte, Brazil, D­22, 04 °15’02’’S, 37°12’37’’W, 206 m, muddy bottom, 10.xi.2001; 1 specimen, LMU­ FRPE 0 0 7, along the state of Rio Grande do Norte, Brazil, D­26, 06 °14’04’’S, 34°52’33’’W, 510 m, muddy bottom, 16.xi.2001.

Type locality: along the state of Rio Grande do Norte, Brazil, D­29, 06 °13’22’’S, 34°52’20’’W, 223 m, muddy bottom, 26.xi.2001

Diagnosis: Protoconch with 1.5 whorls, teleoconch with 3.5 whorls; first whorl with two strong spiral cords, crossed by equally strong ribs; penultimate whorl with 6 spiral cords, the third of which forms the shoulder and the last of which is slightly nodulose. Body whorl with 7 spiral cords, upper third cord forming the shoulder. Base with seven smooth spiral cords, last 3 of which form the fasciole. Notched base, outer lip with 4 lirae, columella with 2 folds.

Description: White, spindle­like, conical shell (Lt 3.2–4.1 mm), with strongly axially and spirally ornamented convex whorls (Figs. 12–14). Smooth, globular, paucispiral protoconch, with nucleus slightly raised in relation to subsequent whorls, composed of 1.5 well­defined whorls and well­marked transition to teleoconch by the emergence of nodulose spiral cords (Figs. 16–17). Teleoconch with 3.5 whorls. First postnuclear whorl marked by 2 strong spiral cords crossed by well developed axial ribs, distributed from suture to suture. Spiral cords positioned medially, leaving a sub and supra­sutural gap with no spiral ornamentation. Penultimate whorl with 2 thin subsutural cords before nodulose shoulder, crossed by 10 strong axial ribs. Below shoulder are 3 spiral cords, the last of which is slightly nodulose and supra­sutural, upper two resembling one another and slightly thinner than shoulder. Strong axial ribs delimiting broad, spirally developed interspaces. Ample body whorl, ornamented by 2 slight subsutural spiral cords, a thin, nodulose shoulder cord and 4 equally nodulose spiral cords, the last thinner. All spiral ornamentation crossed by 8 strong axial ribs. Nodules on cords of body whorl developed spirally over ribs. Well­marked suture. Ribs of body whorl extending downward, stronger on last spiral cord. Conic, sharp base, ornamented by 7 spiral cords with smoother appearance than the upper cords, first base cord emerging from interior of aperture and three last ones forming short siphonal fasciole. Elliptic aperture, widened on posterior side. Small outer lip with 4 elongated internal lirae, not reaching edge. Narrow umbilicus in form of fissure. Strongly reflected parietal region, but without formation of a callus. Straight columella, with 2 folds, uppermost slightly stronger. Short, siphonal canal, sharp on anterior side (fig. 15).

Etymology: In homage to Mr. Richard E. Petit for the generic identification of the species described in the present article.

Geographic distribution: From the state of Ceará to the state of Bahia, along the Fernando de Noronha archipelago, Northeast Brazil, 206– 720 m.