Scaphander planeticus Dall, 1908

(Figs 14, 15; Table 2)

Scaphander (Sabatina) planeticus Dall, 1908: 241 .

Taxonomic history: Scaphander planeticus was described by Dall (1908) based on one juvenile specimen collected in the Central Pacific Ocean during the Albatross expedition. Dall (1908) designated it as the type for his new subgenus Sabatina, which he created to separate extant Scaphander species with strong parietal callus from similar fossil species. Only one specimen has ever been recorded.

Type material: Scaphander (Sabatina) planeticus Dall, 1908 — Central Pacific Ocean: Albatross expedition, station 3684, 0°50 ʹ 00"N, 137°54 ʹ 00"W, 4504 m, holotype, USNM 110748, H = 8 mm, images seen (Fig. 14A) .

Diagnosis: Shell ovoid, white, inflated posteriorly. Small, raised spire. Spiral sculpture composed of punctuated striations.

Shell (Fig. 14): Max H observed = 8 mm. Shell ovoid, wider towards posterior end. Aperture wide, nearly as long as shell, narrowing posteriorly. Small raised spire of three whorls. Shallow suture partly separating spire from body whorl, widening in a narrow groove along uppermost part of parietal wall. Posterior edge of outer lip joining body whorl immediately below spire in rounded shoulder. Parietal wall covered with thick, smooth white callus. Spiral sculpture composed of punctuated striations.

Radula: Unknown.

Digestive tract: Gizzard plates ‘of the same type as those of S. lignarius ’ (Dall 1908) .

Male reproductive system: Unknown.

Ecology: Found at 4504 m. Feeding habits unknown.

Distribution (Fig. 15): Central Pacific (0°50 ʹ N, 137°54 ʹ W).

Remarks: To our knowledge, the holotype is the only specimen that has been sampled for this species. The general shape of the shell, and the raised spire in particular, would suggest close relationships with S. grandis and S. tortuosus, but it is difficult to assess the status of these relationships without additional anatomical or molecular information.