Lafoea coalescens, Allman, 1877

Calder, Dale R., 2019, On a collection of hydroids (Cnidaria, Hydrozoa) from the southwest coast of Florida, USA, Zootaxa 4689 (1), pp. 1-141 : 35-36

Family Incertae Sedis

Genus and species indeterminate

Fig. 8d

Material examined. Southwest Florida Shelf, outer shelf northwest of the Dry Tortugas, 25°16.83’N, 83°57.35’W, 127 m, on Lafoea coalescens , 03 August 1981, triangle dredge, one pedicel and hydranth, 0.5 mm high, without gonophores, coll. Continental Shelf Associates, ROMIZ B4355.

Remarks. This material has been treated as unidentifiable in having a somewhat damaged hydrotheca, a single pedicel, a short length of stolon, and few distinguishing characters. Eucuspidella pedunculata Allman, 1877 , originally described from a depth of 260 fathoms (475 m) off Tortugas, was considered but ruled out as a possibility. Hydrothecae of that species are fusiform rather than tapered towards the base, as in this hydroid, and hydranth pedicels are shown in the original account by Allman (1877) to be smooth throughout rather than being annulated at the base. While also resembling certain species of Egmundella Stechow, 1921b , no nematophores were observed as in that genus.

The operculum of this miniscule hydroid (0.5 mm high) was indistinctly demarcated from the hydrothecal rim. Crease lines at the intersection of the two structures were invisible in lateral view, although they were seen in apical view. Meanwhile, a thin line observed at the base of a hydranth remnant may have marked the location of a thin diaphragm. The specimen is illustrated ( Fig. 8d ) for possible future reference.

Figures

FIGURE 8. a, Hebella venusta: hydrotheca, pedicel, and stolon, Southwest Florida Shelf, ROMIZ B1929. Scale equals 0.1 mm. b, Modeeria rotunda: hydrotheca, pedicel, and stolon, Southwest Florida Shelf, ROMIZ B4350. Scale equals 0.2 mm. c, Eutima sp.: hydranth and stolon, Sanibel Island, ROMIZ B4349. Scale equals 0.1 mm. d, Genus and species indeterminate: hydrotheca, pedicel, and stolon, Southwest Florida Shelf, ROMIZ B4355. Scale equals 0.1 mm.