Hornera verrucosa

DIAGNOSIS. — Apertures circular, alternating, forming more or less transverse rows. Cancelli of almost the same size, one proximal and one distal to the aperture. Dorsal side of colony with rare, scattered cancelli and anastomosing, wide, smooth nervi. Gonozooecia lacking in the Stoliczka specimens.

REMARKS Owing to poor preservation and the lack of a gonozooecium, plus the unrecognisable type material of Reuss (1847), the species cannot be clearly identified. Moreover, Hornera verrucosa seems to represent an unresolved nomenclatural problem. Reuss (1847) described Hornera verrucosa as occurring in the Vienna Basin (Miocene). Reuss (1851) later described other specimens from the Miocene of Poland as Hornera verrucosa [but not sensu Reuss (1847)] and, moreover, further described Hornera verrucosa sensu Reuss (1851) from Söllingen (Oligocene). Reuss (1866) stated that the species occurred from Early through Late Oligocene and the Miocene, even though all these specimens may represent different species. Smith et al. (2008) synonymized these three descriptions as one species (sensu Reuss 1847). Resolving this problem requires a thorough revision of the whole concept of Neogene Hornera, which is beyond the scope of this paper. Because of this imprecise determination of the species, Hornera verrucosa has subsequently often been reported from Neogene (e. g., Bobies 1958; Vávra 1977; Zágoršek 2010) as well as Eocene sediments (Zágoršek 2001, 2003).

MATERIAL EXAMINED. — Two syntypes of Hornera porosa registered as 1862 / 0022 / 0048. Owing to the lack of gonozooecia and unclear attribution of the species, no lectotype has been selected.