Emertonius Peckham & Peckham, 1892

Prószyński, Jerzy, 2018, Review of genera Evarcha and Nigorella, with comments on Emertonius, Padilothorax, Stagetillus, and description of five new genera and two new species (Araneae: Salticidae) *, Ecologica Montenegrina 16, pp. 130-179 : 165

Gen. Emertonius Peckham & Peckham, 1892

Figures 19A, C , 21 A-P, 22G, 25A-H, 26

Type species Emertonius exasperans Peckham & Peckham, 1892 .

Diagnosis. Key characters including habitus (see Figs. 19A , 21 , 25 A-E), differing from that of the type species of genus Myrmarachne ( Fig. 19B and elsewhere in literature). Palps confront to general appearance of 180 species of informal group MYRMARACHNINES, with minor differences, insufficient to separate genera and/or species. Internal structure of epigyne ( Figs 19 C-D, 21A-P) is strikingly different from that of Myrmarachne ( Figs 19 J-O, 22A-E1).

Definition. Emertonius is a characteristic genus, related to Myrmarachne but differing strikingly by body shape and color pattern, (documented on Figs 19A ), in type species not ant-like, in other species ant-likeness is not apparent (compare with type species of Myrmarachne Fig. 19B ). The most important difference is internal structure of epigyne, in Emertonius and a few "lesser" genera, sclerotized spermatheca consist of spherical chamber atop of narrow, petiole like part ( Fig. 19 D-H, 22G-L), while in 104 species of Myrmarachne the spermathecae have characteristic form of two parallel, sclerotized “pipe- like” structures, running medially along the whole length of epigyne, with striking detour in anterior third of the "pipe " in a form of a loop, entangled knot, or double spiral (sample of rich variety of these is shown on Figs 19 J-O, 22A-E1). Transparent, membranous copulatory ducts, very entangled and long, running from copulatory openings to junction with spermathecae, are usually overlooked and not mentioned in descriptions because they are visible only on cleared and stained (by Chlorazol Black B) microscope slides (even perfect photographs by Yamasaki do not display them - Figs 19 D-O). In difference to spermathecae, palps are largely uniform in some 180 species of MYRMARACHNINES (see Prószyński 2017b: 99), almost useless for separation of genera and identification of species.

Remarks. Diversity of spermathecae within Emertonius and other "lesser genera" require further comparative research in order to distinguish it from intra-populational variation, whose sample is shown on Fig 26 A-J1.

Composition. Type species Emertonius exasperans Peckham & Peckham, 1892 (Java and Bali), Evacin besar sp. n., Emertonius koomeni sp. n. - Borneo, Emertonius malayanus ( Edmunds & Prószyński, 2003) comb. n. (Sumatra, Borneo), " Emertonius" palawanensis sp. n. (placement provisional, from Philipines: Palawan), Emertonius shelfordi (Peckham & Peckham, 1907) comb. n. - Borneo.

Figures

Figure 19. Diagnostic criteria of genera of informal group MYRMARACHNINES. A - Emertonius exasperans - type species, A1 - Edward's opinion on identity of Emertonius with Myrmarachne, B - Myrmarachne melanocephala - type species, C - Emertonius exasperans, D - Emertonius shelfordi, E - Myrmage, F - Myrmatheca, G - Toxeus epigealis, H - Toxeus maxillosus, I - Myrmavola, J - Myrmarachne acromegalis, K - Myrmarachne assimilis, L - Myrmarachne biseratensis, M - Myrmarachne cornuta, N - Myrmarachne macrognatha, O - Myrmarachne hanoi. For characters of more species see Figs 21 and 22.

Figure 21-I. For figure caption see under Figure 21-II.

Figure 25-I. For figure caption see under Figure 25-II.

Figure 26-I. For figure caption see under Figure 26-II.