Nemausa acuticornis (Stimpson, 1871)

(Fig. 11A)

Mithrax acuticornis Stimpson, 1871: 116 [type-locality: Tortugas; type not found]; A. Milne-Edwards 1875: 98; Miers 1886: 86; Rathbun 1901: 512, fig. 8; 1901: 66; 1933: 29, fig. 28; Jones 1969: 380; Abele & Kim 1986: 522, 523, figs. f–g.

Mithrax (Mithrax) acuticornis .— Rathbun, 1925: 388, pl. 136, figs. 1–2, pl. 257, fig. 1; Boone 1930: 93, pl. 29, fig. A; Coelho 1971: 140; Coelho & Ramos 1972: 214; Felder 1973: 52, pl. 7, fig. 10; Powers 1977: 56; Williams 1984: 322, figs. 267, 275a; Keith 1985: 259, fig. 5B.

Nemausa acuticornis . — Melo 1996: 241, unnumbered fig.; Carré 2005: 23; Ng et al. 2008: 120; Alves et al. 2012: 943; Lira et al. 2013: 55, tab. 1; Windsor & Felder 2014: 147, tab. 1, 152, 156, fig. 3J, 157, fig. 4K; Klompmaker et al. 2015: 3, tab. 1; Poupin 2018: 196; Mantelatto et al. 2020: 42.

Distribution. Western Atlantic: USA (North Carolina to Florida), Gulf of Mexico, Bermuda, Hispaniola, St. Croix, St. John, Montserrat, Dominica, Barbados, Martinique, St. Vincent, Tobago, Curaçao, Panama, and Colombia (Wagner 1990; Carré 2005; Poupin 2018; Mantelatto et al. 2020).

Material examined. Barbados, Drill Hall, St. Michael, nearshore rubble, 13°04’36.30”N, 59°36’26.63”W, 5 Ô CW: 5.4, 6.2, 4.4, 7.2, 4.7 mm (BLSZ 126) . Idem, 2 Ô CW: 5.7, 4.7 mm (BLSZ 181) . Idem, 1 Ô CW: 5.3 mm (BLSZ 057) . Idem, 2 Ô, 1 ♀ CW: 1.2, 1.3, 1.0 mm (MZUSP 40910) .

Remarks. Specimens of Nemausa acuticornis were collected by hand in nearshore rubble habitat, under rubble rock at low tide, on the west coast of Barbados. Nemausa acuticornis was observed under the same rubble rock as Eriphia gonagra, Mithraculus coryphe, Nemausa cornuta, Amphithrax aculeatus, Amphithrax verrucosus, Cataleptodious floridanus, Paractaea nodosa, and Pachygrapsus transversus . Rathbun (1921: 83) reported one juvenile (USNM 72147) specimen of Nemausa acuticornis collected during the Barbados-Antigua Expedition in 1918. The Smithsonian-Hartford Expedition in 1937 collected seven juvenile specimens of Nemausa acuticornis from Barbados (USNM 75184) and Jones (1969: 80) also reported this species for Barbados. Wagner (1990: 6– 10) included Nemausa acuticornis in the synonym list for the species Nemausa cornutus; however, Felder et al. (2009: 1077, 1099; note nº 308) listed Nemausa acuticornis and Nemausa cornuta as separate species. We follow the decisions of Felder et al. (2009) and Poupin (2018) herein and recognise Nemausa acuticornis and Nemausa cornuta as different species. Nemausa acuticornis can be identified by the presence of two supra-orbital spines between the preorbital and postorbital spine (Rathbun 1925).