Disk pentagonal (dd = 2.63 to 3.03 mm). Covered by imbricating scales of different sizes (Fig. 6a). Radial shields narrow, three times as long as wide, almost completely separated by two or three broad and elongated scales (Fig. 6a). Ventral interradius covered by scales similar to dorsal, but slightly smaller (Fig. 6b). Bursal slits narrow. Oral shields longer than wide, tending to be diamond-shaped (Fig. 6c). Adoral shields enlarged laterally. Two oral papillae on each side of jaw angle, distal spatuliform and proximal spiniform, the latter positioned more internally on jaw (Fig. 6c). Dorsal arm plate slightly wider than long, proximal angle acute and distal margin rounded, tending to be fan-shaped (Fig. 6d). Ventral arm plate rectangular and narrow (Fig. 6e). Four to five subequal arm spines, crown of denticles on tip. One small tentacle scale (Fig. 6e).

The Bahamas, the islands off southern Florida, west coast of Florida, Texas offshore reefs, the Antilles, Belize, islands off Caribbean Colombia, and Brazil (Hendler et al. 1995, Chavarro et al. 2004, Alvarado et al. 2008). In Brazil from Amapá, Maranhão, Ceará, Bahia (Gondim et al. in press), Rio de Janeiro (Rathbun 1879), and São Paulo (Netto et al. 2005). Depth 1 to 126 m. Recorded herein for the first time in the State of Paraíba, between 10 and 18 m.

Hermaphroditic and viviparous species. It lives in bottoms of mud, sand, calcareous algae (Tommasi 1970), and gravel of corals and shells (Abreu-Pérez et al. 2005). Two species of genus Amphiura are known for the litoral of northeastern Brazil, Amphiura stimpsoni and Amphiura kinbergi Ljungman, 1872. The latter is recorded only for the states of Alagoas and Bahia (Lima et al. 2011, Manso et al. 2008). Amphiura stimpsoni differs formits congener Amphiura kinbergi in the number of tentacle scales (one in Amphiura stimpsoni and two in Amphiura kinbergi) and in the number of arm spines (six to seven in Amphiura kinbergi). Personal observations suggest that this species is rare along the littoral of Paraíba, both in shallow coastal waters as in deeper isobates (up to 35 m).