Acherontides

Type species: Acherontides atoyacensis Bonet, 1945 Thibaud et al. 2004 amended the original diagnosis bv Bonet 1945 as follow: small Hypogatruridae with body length about 1 mm; without pigment, eyes, PAO. or empodium. Furca reduced, mucrodens with 1 or 2 chaetae, mucro degenerate sometimes totally absent. Antennae cylindrical, nearly as long as the head. Ant. III O. with 2 very small sensilla, more or less hidden by a tegumentary fold and surrounded by 2 much longer guard sensilla. Ant. IV with 3 - 5 well developed sensilla. Retinaculum with 3 + 3 or 2 + 2 teeth. Two small anal spines on basal papillae. Chaetotaxy of Type I consisting of short, more or less serrated chaetae and longer and fine sensory chaetae. Dorsal Th. I with 3 + 3 chaetae; Th. II and III with 3 rows of chaetae (a 4 + 4, m 3 + 3, p 4 + 4, ss at p 4, without lateral microsensillum on Th. II). Abd. I-III with 2 rows (a 4 + 4, p 5 + 5 and lateral ss at p 6). Abd. IV with 2 or 3 rows (a 3 + 3, m 0 + 0 or 1 + l, p 4 + 4 and lateral ss at p 5). Ventral tube with 4 + 4 chaetae. Here we extend the genus to include the species with body length 700 – 1600 µm; Th. I with 3 + 3 to 4 + 4, Th. II and III with 3 rows of chaetae (a 4 + 4 to 7 + 7, m 3 + 3 to 4 + 4, p 4 + 4 to 5 + 5, 1 or 2 ss, without lateral microsensillum on Th. II). Abd. I-III with 2 rows (a 4 + 4 to 6 + 6, p 5 + 5 to 8 + 8 and a lateral ss). Abd. IV with 2 or 3 rows (a 3 + 3 to 5 + 5, m 0 + 0 to 3 + 3, p 4 + 4 to 6 + 6 and lateral ss).