dcsimg

Description

provided by NMNH Antarctic Invertebrates

“Genus Laevilacunaria n.g.

Type : Pellilitorina bransfieldensis Preston
(See above for diagnosis)”

(Powell, 1951:108)

Genus Laevilacunaria n. g. (Type: Pellilotorina bransfieldensis Preston), South Shetlands. Shell larger than that of Laevilitorina, depressed, heliciform with a wide umbilicus and smooth epidermis. Radula (Fig. I, 29) with a narrow central tooth, central and lateral teeth with broad chisel-shaped main cusps and weak side denticles, marginals foliate with few denticles. Includes Lacuna antarctica Martens from South Georgia and possibly Hydrobia pumilis Smith from Swains Bay, Kerguelen Island.

Since these southern Littorinids vary in shape between ovate-conical and depressed helicoid forms, even within one radula group, the use of the northern genus name Haloconcha for this group, merely upon external resemblances, is undesirable. Until some knowledge of the animal of Haloconcha is available it is more satisfactory to disassociate the southern shells under a new generic name.”

(Powell, 1951: 106-107)