Shell cap-shaped, oval, thin. Apex between 80 and 95% of length, base strongly arched and convex, sculpture of concentric growth lines only. Protoconch with long and narrow apical fold and fused tip; sculpture of about 12 longitudinal cords and minute punctae near lip. Radula and anatomy unknown.

Bogi (1984) included the type species of this genus (C. labronica) in the genus Cocculina Dall, 1882, on the basis of the similarity of the shell. He pointed out that the apex is eroded and that the new species resembles Lepetella taterocompressa in variability and habitat. The protoconch of C. labronica, in spite of Bogi's (1984) description, is not eroded but well preserved in two of the five paratypes studied. He added that the strongly arched base is only found in the genus Tectisumen Finlay, 1927, from New Zealand, but in contrast is there convex and not concave laterally. As discussed above, Tectisumen is considered a synonym of Lepetella by most authors. Also, Bogi (1984) compared C. labronica with Pectinodonta arcuata Dall, 1882, from the West Indies, and said that the latter species is much less concave, and has a subcentral apex. Finally, Bogi (1984) proposed If, as it seems to be, this species belongs to a new subgenus, the name Antitectisumen n. subgen.'.
Rocchini (1990) maintained C. labronica in the genus in which it was originally described and Sabelli, Giannuzzi-Savelli & Bedulli (1990) included this species, without any justification, in the genus Lepetella Verrill, 1880.
In our opinion, on the basis of unique shell charac¬ters, C. labronica does not belong to the family Lepetellidae because, as far as we know, the lepetellids do not retain the protoconch at this size. Moreover, the only larval shell of Lepetella illustrated until now (Warén, 1991: 82, fig. 6B) is distinctive, with reticulate sculpture. On the other hand, C. labronica is not a Pectinodonta (Acmaeidae, Pectinodontinae), because this genus has a deciduous protoconch and strong concentric sculpture (Marshall, 1985).
According to Haszprunar (1988b), the Cocculinidae are characterized by a protoconch with a short and broad apical fold and a free tip, whereas the Pseudococculinidae have a protoconch with a long and narrow apical fold and a fused tip. The two families are, however, much better differentiated by radular and anatomical features (Haszprunar, 1988b). Cocculina labronica seems to have a pseudococculinid protoconch, but we prefer not to include it in any family at this stage, awaiting anatomical information. In any case, the characteristic sculpture of the protoconch of this species does not resemble any of the described genera of cocculinids or pseudococculinids. Therefore, we consider that C. labronica must be included in a new genus. The name Antitectisumen Bogi, 1984 is not available because it was proposed conditionally after 1960 (ICZN, art. 15). For this reason, we propose the new genus Bogia to include Cocculina labronica Bogi, 1984, basing the diagnosis only on shell characters.