Calveriosoma hystrix (Thomson, 1872b) Reports for the Azores: Asthenosomum hystrix (Agassiz 1881) — $ Koehler 1895a: 224, 1895b: 228; Asthenosomum hystrix (Thomson, 1872b) — $ Koehler 1898: 9–10; Areosoma hystrix (Thomson, 1872b) — $ Koehler 1909: 216–217; Mortensen 1927a: 282–283, figs. 156.1, 158.2, 159; Nobre 1938: 107–108, fig. 47; Calveriosoma hystrix (Thomson, 1872b) — Mortensen 1935: 222–227, figs. 126–128, pl. 23, figs. 1–5, pl. 24, fig. 1, pl. 68, fig. 12; $ Pérès 1992: 252, 254; García–Diez et al. 2005: 50. Type locality: between Faeroe Island and Scotland (59°26’N, 8°23’W). See: Mortensen (1903: 70–72, as Calveria hystrix; 1935). Occurrence: Northeast Atlantic, from off SW Iceland (Mortensen 1903) southwards to Northeast African waters (Koehler 1909, Mortensen 1927b), including the Azores (Koehler 1909), and the Canaries (Mortensen 1927b), and Meteor seamounts (Koehler 1898). Depth: 360– 1,800 m (Mortensen 1935); AZO: 800– 1,528 m (Koehler 1898, 1909). Habitat: on sand, mud to soft ooze (Koehler 1898, Gage et al. 1985). Larval stage: lecithotrophic (Emlet 1995). Remarks: historically, Calveriosoma hystrix was frequently confused and in many instances regarded as conspecific with Araeosoma fenestratum (Mortensen 1903, 1935), another echinoid native to the archipelago deep waters (see above). As a result, older records particular prior to the review by Mortensen (1903) should be regarded with caution considering that they could be referring to either of the two species.

Published as part of Madeira, Patrícia, Kroh, Andreas, Cordeiro, Ricardo, De, António M., Martins, Frias & Ávila, Sérgio P., 2019, The Echinoderm Fauna of the Azores (NE Atlantic Ocean), pp. 1-231 in Zootaxa 4639 (1) on page 119, DOI: 10.11646/zootaxa.4639.1, http://zenodo.org/record/3342161