Amphiodia riisei (Lütken 1859)

Disk circular (dd = 4.16 mm). Covered by numerous imbricating scales of irregular shapes (Fig. 4f). Primary plates very conspicuous (Fig. 4f). Central primary plate slightly pentagonal, surrounded by the radial primary plates. Radial shields enlarged distally, contiguous, except at proximal end, where there is a small, elongate, triangular scale (Fig. 4f). Ventral interradius covered by small, imbricating scales (Fig. 4g). Bursal slits long and broadened. Oral shields diamond-shaped (Fig. 4h). Adoral shields enlarged laterally. Two oral papillae on each side of jaw angle, the distal one a little larger than the proximal one (Fig. 4h). Infradental papillae rectangular and robust. Dorsal arm plate broader than long, rectangular, with the distal border rounded (Fig. 4i). Ventral arm plate pentagonal. Three arm spines slightly bigger than one arm segment, which is laterally flattened, with blunt tip (Fig. 4j). Two tentacle scales subequal and perpendicular.

Off Florida, the Antilles, possibly Panama and Puerto Rico, and Brazil (Hendler et al. 1995). In Brazil from Amapá, Pará (Albuquerque 1986), Bahia (Magalhães et al. 2005), Rio de Janeiro (Lütken 1859, type locality), São Paulo (Tommasi 1970), and Paraná (Borges and Amaral 2005). Depth 1-311 m. Found for the first time in the State of Paraíba, at 16 m, in the present study.