Hydrometra argentina Berg, 1879

(Figs. 12B, 13A–F)

Hydrometra argentina Berg, 1879: 182 (original description).

Identification. Our specimens were identified based on the body length less than 12 mm; the clypeus narrow and conical, with the anterior margin not excavated (Fig. 13B); the lateral surface of the pro- and mesoacetabula with at most three circular pits each (Fig. 13D); and male abdominal sternum VII with a pair of spinose projections near the anterior margin (Figs. 13E–F) (Moreira & Barbosa 2013; Martínez et al. 2019).

Examined material. BRAZIL, Rio Grande do Norte: Ceará-Mirim, Rio Ceará-Mirim, 5°37’50.4”S, 35°25’16.9”W, 21-IX-2019, R.P. R. Canejo, A.L. Melo leg. (2♀ macropterous CEAAVF); Itajá, açude em Itajá, 5°43’36.0”S, 36°46’20.9”W, 02-X-2020, R.P. R. Canejo leg. (1♀ brachypterous CEAAVF) ; Natal, UFRN, espelho d’água da reitoria, 5°50’21.8”S, 35°12’04.7”W, 05-III-2020, R.P. R. Canejo leg. (1♀ macropterous CEAAVF) ; Macaíba, Riacho do Sangue, 5°51’58.5”S, 35°21’46.1”W, 24-XI-2019, R.P. R. Canejo leg. (1♂ brachypterous CEAAVF) ; Poço Branco, Rio Ceará-Mirim - Represa, 5°38’00.5”S, 35°39’11.0”W, 21-IX-2019, R.P. R. Canejo, A.L. Melo leg. (2♀ macropterous CEAAVF) ; Santana do Matos, Açude Alecrim, 5°57’51.3”S, 36°39’26.0”W, 28- XI-2019, R.P. R. Canejo leg. (1♀ brachypterous CEAAVF) ; Serra Negra do Norte, ESEC - Seridó, Casa da Entrada, [coordenates unknown], 20/ 21-VIII-1999, A.A. Varela-Freire leg. (2♀ macropterous CEAAVF) ; Serra Negra do Norte, Rio Espinharas, 26-IX-2019, A.L. Melo leg. (1♂ macropterous DPIC) ; Touros, Lagoa do Jiqui 02-XI-2018, R.P. R. Canejo, A.L. Melo leg. (1♂ brachypterous DPIC) .