Kleokyphus callimus Solem, 1976

Sartori, André F., Gargominy, Olivier & Fontaine, Benoît, 2014, Radiation and decline of endodontid land snails in Makatea, French Polynesia, Zootaxa 3772 (1), pp. 1-68 : 28-30

Kleokyphus callimus Solem, 1976

Figures 18 ; 19; 35K; 37D; 39.

Libera heynemanni (Pfeiffer) —Aubert de la Rüe & Soyer 1958, p. 365, non Helix heynemanni Pfeiffer 1862 . Kleokyphus callimus Solem 1976 , pp. 224–226, table 75, figs 95a–c

Examined material (10 specimens). Holotype: MNHN 25568. Tuamotu Islands: Makatea. Collected by E. Aubert de la Rüe in 1955. Paratypes: MNHN 25569, 1 shell, from the type locality. FMNH 153781, 2 shells, from the type locality. Additional material: MNHN 25570, 6 shells, Mk16.

Diagnosis. Shell less than 5 mm in diameter, depressed, flammulated; apical suture adpressed; teleoconch sculptured by narrow, very low, relatively crowded primary axial ribs (> 90 ribs on body whorl); umbilicus Ushaped, slightly constricted at last whorl; palatal wall with 6 barriers and 2 traces; parietal wall with 4 barriers and 1 trace, rarely with 3 barriers and 3 traces.

Type locality. Tuamotu Islands: Makatea.

Description. Shell depressed, white, with regularly spaced, amber flammulations fading out on the shell base. Shell wall thin, opaque; periostracum adherent, matt. Apex flat, spire elevated; whorls descending progressively more rapidly. Periphery slightly angulated; supraperipheral wall broadly convex; infraperipheral wall rounded, smoothly transitioning into basal and columellar walls. Apical suture adpressed, umbilical suture impressed. Transition between protoconch and teleoconch indistinct. Sculpture of the first whorl unknown; second whorl ornamented by narrow axial riblets, with interspaces 6–8 times their width. From the third whorl onwards, primary sculpture composed of very low, relatively wide axial ribs, with interspaces 3–8 times their width, more prominent on the shell base than apically; primary ribs overlaid by a secondary axial sculpture of crowded, very low, wavy riblets, with interspaces c. 1/2-2 times their width, and by minute spiral cords. Umbilicus very deep, U-shaped, slightly wider apically than at last whorl. Peristome crescent-shaped; columellar lip slightly reflected. Palatal wall with 2 traces and 6 barriers; traces slightly recessed within aperture, very low; trace 1 columellar, extending inward beyond the line of vision from the peristome; trace 2 just below apical suture, extending c. 1/8 whorl; palatal barriers approximately equidistant along infraperipheral, basal and columellar walls; barriers 1, 2 and 6 slightly recessed; barriers 1 and 6 less prominent than the others; barrier 1 columellar, descending gradually anteriorly, extending inward beyond the line of vision from the peristome; barriers 2 to 6 extending c. 1/8 whorl, descending gradually anteriorly and posteriorly; barriers 2 to 5 not recessed, similar in prominence. Parietal wall usually with 1 trace and 4 barriers, rarely with 3 traces and 3 barriers; trace 1 just below apical suture, extending inward beyond the line of vision from the peristome, very low; barriers approximately equidistant, extending 1/8 whorl, not recessed, descending gradually anteriorly and posteriorly; barriers 1 to 3 similar in prominence, slightly taller than barrier 4; barrier 4 rarely absent and replaced by two close-set, low additional traces, not recessed within aperture and extending 1/16 whorl. Other shell features that can be expressed numerically are shown in Table 2 .

Remarks. Solem (1976) established K. callimus based on four specimens collected by Aubert de la Rüe from Makatea, without more precise locality data. To these, we add six specimens recovered from station Mk16, bringing the number of known individuals to ten. All agree well with the original description. The holotype, figured here for the first time ( Fig. 18 A), is a small adult specimen with the sculpture comparatively well-preserved but missing part of the palatal wall and barriers. The largest of the paratypes in the Field Museum shows the feeble spiral cording of the species more clearly than any other specimen ( Fig. 19 E). Specimen 1 of our series has two close-set traces in place of the fourth parietal barrier ( Fig. 19 F). Intraspecific variation in other features seems small and not noteworthy. K. callimus is the type species of Kleokyphus Solem, 1976 and the only representative of the genus displaying a shallow, adpressed apical suture, and the sculpture greatly reduced above the periphery.

Figures

FIGURE 18. Kleokyphus callimus. A. Holotype (MNHN 25568); B. Paratype (MNHN 25569); Scale bars = 2 mm.

FIGURE 19. Kleokyphus callimus. A – C. Holotype (MNHN 25568), apical views; A. General view; B. Sculpture of the protoconch and early teleoconch; C. Sculpture of the late teleoconch; D. Specimen 3 (MNHN 25570), detail of the peristome; E. Paratype (FMNH 153781), showing spiral cording on the shell base; F. Specimen 1 (MNHN 25570), detail of the peristome; Scale bars: A, E = 1 mm; B, C = 0.2 mm; D, F = 0.5 mm.