Balanus spongicola spongicola Brown, 1844

Fig. 2 (12–13)

Balanus spongicola, Brown, 1844: 121, pl. 53 figs 14–16

Other references:

B. spongicola, Carriol, 1982: 14, 1992: 146, 1996: 57; De Alessandri, 1906: 277, 1907: 195, 1908: 218; Lecointre, 1910: 137; Menesini, 1984: 298; Menesini & Casella,1988: 250; Newman & Ross, 1976: 66 (long list of references); Relini, 1980: 73; Stubbings: 1963: 22.

Occurrence: Ferrière-Larçon, Pauvrelay (Paulmy commune), Les Bournais (Saint-Laurent-de-Lin commune), Indre-et-Loire, France; faluns of Middle Miocene age.

Material: MNHN A25756: a right scutum; MNHN A25757: a right tergum.

In addition to the figured opercular plates, several unregistered specimens have been observed: complete shells and opercular plates from Saint Laurent-de-Lin commune and fragments of opercular plates from Ferrière-Larçon and Paulmy.

Measurements: MNHN A25756: occludent margin 5.0 mm; MNHN A25757: scutal margin 2.8 mm.

Description: The material studied herein conforms to the description of Stubbings (1963). Shape conical, smooth-walled; orifice toothed owing to oblique margins to radii. Parietal tubes septed. Scutum with prominent growth ridges cut by grooves radiating from apex; internally, adductor pit moderately deep, adductor ridge rather small; depressor muscle pit strongly developed, elongated, with characteristic deep furrow prolonging line of pit towards apex; spur fasciole, broad, truncate, separated by about half its width from basiscutal angle; basal margin on carinal side curves smoothly into spur.