Columbarium quadrativaricosum Harasewych 2004

“Columbarium quadrativaricosum new species

(Figures 7, 18-23)

Diagnosis: A small species with a gradate spire, fusi­form, white shell, with tabulate, squarish whorls, axial sculpture of thick, rounded varices [8-9 per whorl] and spiral sculpture of distinct cords, square in profile, stron­gest on periphery and anterior carina. Inner lip formed by a thickly glazed peristomal plate that overlies the col­umella and proximal siphonal canal.

Description: Shell (Figures 18, 22, 23) small (to 45 mm), thick to moderately thin, fusiform, with squarish varices. Spire angle 46-51°. Protoconch (Figure 20) of about 1½ smooth, glassy whorls. First whorl inflated, de­flected from coiling axis by 67-72°. Transition to teleo­conch distinguished by onset of peripheral keel, rounded at first, becoming keel-like, with broad, undulating axial nodes within ½ whorl. Teleoconch of up to 7 strongly shouldered, nearly tabulate, squarish whorls. Suture adpressed to previous whorl anterior to anterior carina. Earliest sculpture, apart from very fine growth striae vis­ible on all teleoconch whorls, consists of broad, rounded axial nodes along peripheral keel (8-9 per whorl) that become narrower, more sharply defined, supported by axial ribs of increasing prominence by third teleoconch whorl. By fourth teleoconch whorl, axial ribs form broad, solid varies, thickest between peripheral keel and an­terior carina, producing a square whorl profile, with nearly tabulate shoulder. Spiral sculpture first appears on second teleoconch whorl, as single cord below pe­ripheral keel. By third teleoconch whorl, 2-3 weak cords or threads appear above peripheral keel. Body whorl with 4-5 strong, square, equally spaced cords between suture, peripheral keel; 1 strong cord between major cords along peripheral keel, anterior carina; 4-5 cords between anterior carina, siphonal canal; 7-10 cords on proximal ½ of siphonal canal. Finer threads between ad­jacent cords, suture to keel (0 threads); keel to carina (1-3 threads); carina to siphonal canal (1-2 threads), si­phonal canal (0-1 threads). Aperture broadly ovate, nearly rounded, tapering anteriorly, deflected from shell axis by 23-29°. Outer lip thickly glazed, with furrows beneath suture, peripheral keel, anterior carina extend­ing to nearest varix. Inner lip smooth, thickly glazed, peristomal plate overlaying columella, proximal portion of siphonal canal. Siphonal canal long, axial, stout, straight. Shell color uniformly white. Periostracum (Fig­ure 21) thick, amber colored, lamellose. Operculum (Figure 19) thin, ovate, broadly rounded posteriorly, with terminal nucleus. Inner surface with rounded at­tachment area. Soft tissues, radula, unknown.

Type Locality: Off Mendu Point, Transkei, South Africa, 32º21.8’ S, 29º00.0’ E, in 300 m, on coarse sand, R/V MEIRING NAUDÉ, sta. R 10, 12 July 1984.

Type Material: Holotype, NM C 6279, 36.87 mm, from the type locality; Paratype 1, USNM 1018396, 39.79 mm, off Qora River, Transkei Region, Eastern Cape, South Africa, 33°33.6' S, 28°48.8' E, in 300 m, coarse sand, some broken shell, R/V MEIRING NAUDÉ, sta. U 10, 11 July 1984; Paratype 2, NM C 1802, 28.67 mm, off Bulungula River, Transkei Region, Eastern Cape, South Africa, 32°13.7' S, 29°08.7' E, in 250-270 m, muddy sand, old shell debris, R/V MEIRING NAUDÉ, sta. 17 July 1982; Paratype 3, NM C 6377, 27.52 mm, off Mendu Point, Transkei Region, Eastern Cape, South Africa, 32°24.0' S, 28°59.0' E, in 250 m, coarse sand, rubble, few sponges, R/V MEIRING NAUDÉ, sta. R11, 12 July, 1984; Paratypes 4, 5, NM C4911, 44.77 mm, 35.81 mm, off Mendu Point, Transkei Region, Eastern Cape, South Africa, 32°22.6' S, 29°00.4' E, in 250-260 m, dredged on coarse sand; R/V MEIRING NAUDÉ, sta. R 7, 8 June 1983; Paratype 6, NM C9337, 26.75 mm, off Bulungula River, Transkei Region, Eastern Cape, South Africa, 32°14.0' S, 9°08.6' E, in 250-300 m, dredged on coarse sand, R/V MEIRING NAUDÉ, sta. O10, 5 June 1985; Paratype 7, NM C6304, 20.02 mm, off Qora River, Transkei Region, Eastern Cape, South Africa, 33°34.2' S, 28°48.1' E, in 270 m, dredged on old shell bottom, R/V MEIRING NAUDÉ, sta. U 11, 11 July 1984; Paratype 8, NM C6573, 28.40 mm, off Qolora River, Transkei Re­gion, Eastern Cape, South Africa, 32°47.6' S, 28°36.6' E, in 510 m, dredged on sandy mud, R/V MEIRING NAUDÉ, sta. Y 12, 14 July 1984; Paratype 9, NM C6468, 16.46 mm, off Shixini Point, Transkei Region, Eastern Cape, South Africa, 32°31.4' S, 28°52.5' E, in 400-420 m, dredged on coarse sand, fine shell rubble, R/V MEIR­ING NAUDÉ, sta. T 16, 12 July 1984; Paratypes 10, 11, NM C8668, 38.33 mm, 29.35 mm, off Nthlonyane River, Transkei Region, Eastern Cape, South Africa, 32°18.2' S, 20°06.2' E, in 550 m, dredged on sand, stones, broken Dendrophyllia, R/V MEIRING NAUDÉ, sta. P 13, 5 July 1985; Paratype 12, NM C8946, 33.39 mm, off Mgazi River, Transkei Region, Eastern Cape, South Africa, 31°44.3' 5, 29°32.2' E, in 250 m, dredged on muddy sand, R/V MEIRING NAUDÉ, sta. J 11, 4 July 1985.

Distribution (Figure 7): Columbarium quadrativaricosum has been collected at multiple stations, all in a narrow range [31º34’-33º34’ S] off the Transkei Region, Eastern Cape, South Africa, at depths ranging from 250 to 550 m. Specimens from depths in excess of 420 m were all dead collected and extremely worn.

Etymology: quadrativaricosum = quadratus—Latin, squared + varicosus—Latin, varicose or ridged.

Remarks: Columbarium quadrativaricosum is related to the group of southern African congeners character­ized by the presence of thick, rounded varices, including C. subcontractum (Sowerby, 1902), C. formosissimum Tomlin, 1928, and C. natalense Tomlin, 1928. It most closely resembles C. subcontractum, which inhabits a similar bathymetric range, but appears to be allopatric, based on limited records that indicate a range to the north of Durban Bay. While these two species reach comparable shell length, C. quadrativaricosum has a thinner shell, a proportionally shorter, more gradate spire, a smaller, rounder aperture, a longer, thinner si­phonal canal, a tabulate shoulder, and varices that are squarish rather than triangular. It also closely resembles C. natalense, which has a comparable geographic range, but inhabits shallower depths [90-160 m]. Columbarium natalense can be distinguished from C. quadrativaricos­um based on its pigmented shell (reddish brown with lighter spiral cords and distal portion of siphonal canal), spiral sculpture of cords that are not continuous, but posteriorly recurved along each varix, the presence of a long, open spine at the shoulder of each varix, and an extremely pronounced cord along the anterior carina. The much larger C. formosissimum, which has a more southerly distribution [Cape St. Blaize to Port Alfred] and shallower bathymetric range [121-165 m], may also be distinguished by it heavier proportions more similar to C. subcontractum, its reduced or absent spiral sculp­ture, and its weaker varices that develop at a larger shell size.”

(Harasewych, 2004: 98-100)

Columbarium quadrativaricosum is a species of large sea snail, marine gastropod mollusk in the family Columbariidae.