Two new species of Anamastigona from Cyprus and an updated key to species of the genus (Diplopoda: Chordeumatida: Anthroleucosomatidae)

Abstract. Two new species of the millipede genus Anamastigona are described, A. cypria sp. nov. and A. strasseri sp. nov., both from the island of Cyprus. The new species are considered to be most similar to A. terraesanctae Golovatch & Makarov, 2011 from Israel, the three of them forming a species group which is briefly characterized. An updated key to all 20 recognized species of the genus Anamastigona is provided and a short overview of the taxonomy of the genus is given.


Introduction
The millipede genus Anamastigona Silvestri, 1898 (Chordeumatida: Anthroleucosomatidae) is hitherto known to comprise 17-19 species native to the Apennine and Balkan peninsulas, several Mediterranean islands, the northwestern Aegean coast of Turkey, Israel and the Caucasus, with one species, A. pulchella (Silvestri, 1894), showing a broader, scattered distribution across western Europe, probably a result of human activity.
The name Anamastigona has a long history dating back to Silvestri (1898), followed by numerous, mostly single-species descriptions and redescriptions by various authors, until the last two members of the genus -A. mauriesi and A. terraesanctae -were described by Golovatch & Makarov (2011). The latest comprehensive work on the genus in the framework of a review of the family Anthroleucosomatidae is that by Ćurčić et al. (2008). These authors presented a key to the species of Anamastigona, as part of a key to the genera and species of Anthroleucosomatidae, and suspected that A. aspromontis (Strasser,

Diagnosis
A genus of the family Anthroleucosomatidae characterized by a body consisting of 29 segments plus the telson and by the following gonopodal characters: caudal face of anterior gonopods with lamellar central part, but without well-developed syncoxite, and with colpoxites; posterior gonopods with welldeveloped, strongly chitinized angiocoxites and with usually more or less membranous colpoxites.

Diagnosis
Resembles its most similar congeners -A. terraesanctae and A. strasseri sp. nov. -by the anterior gonopods possessing well-developed colpocoxites and an elaborate median lamella, which is more or less densely covered with long, setiform fi laments; and by the posterior gonopods consisting of large, relatively stout angiocoxites, bearing several setae and rather prominent telopodital rudiments, and of fi ne, membranous colpocoxites. Differs from them by being on average slightly smaller, with a somewhat darker colouration, and by certain details of gonopod structure, namely, the lateral arms of the anterior gonopods branching distally into 2 processes and by the presence of a subapical unciform process on the angiocoxites of the posterior gonopods; further morphological differences between the 3 species are summarized in Table 1.

Etymology
The epithet of this new species emphasizes its provenance from Cyprus.

Diagnosis
Resembles its most similar congeners -A. terraesanctae and A. cypria sp. nov. -by the anterior gonopods possessing well-developed colpocoxites, and an elaborate median lamella, which is more or less densely covered with long, setiform fi laments; and by the posterior gonopods consisting of large, relatively stout angiocoxites, bearing several setae and rather prominent telopodital rudiments, and of fi ne, membranous colpocoxites. Differs from them mostly by the lateral arms of the anterior gonopods being blunt and barely bent caudad, rather than tapering and strongly bent caudad. Further morphological differences between the 3 species are summarized in Table 1.

Etymology
This species is named in memory of Karl Strasser (1903-1981, a prominent myriapodologist who, among other things, described several species of Anamastigona.

Remarks
The position of the posterior gonopod colpocoxites in this species is unusual -they are almost completely oriented one behind the other, rather than next to each other, i.e., more perpendicular than parallel to the sternal axis. However, in the presence of only one examined male, this peculiarity may represent nothing more than individual variation.

Discussion
Anamastigona terraesanctae, A. cypria sp. nov. and A. strasseri sp. nov. appear to be a natural group characterized by the above described diagnostic features, as well as by generally similar morphometrics and colour pattern. This is yet another example of the considerable similarity between the millipede faunas of Cyprus and the Levant (Vagalinski et al. 2014). Interestingly, A. strasseri sp. nov. seems to occupy a morphologically intermediate position between A. terraesanctae and A. cypria sp. nov., sharing the uniramous lateral arms of the anterior gonopods and the stout, apically broad angiocoxites of the posterior gonopods with the former species, but the very long and dense pilosity on the median lamella and the elongated colpocoxites of the anterior gonopods with the latter.
At present, the exact number of species within Anamastigona remains uncertain. As already mentioned in the introduction, the proposed synonymy of A. aspromontis (Strasser, 1970) with A. meridionalis Silvestri, 1898 does not seem to be solid enough. There are a number of differences concerning the gonopodal apparatus that can hardly be considered as mere individual variations: the anterior gonopods in A. aspromontis have a more narrow median plate/lamella and bear two slender, apically branched processes positioned between the colpocoxites and the lamella, these being absent in A. meridionalis; and, most importantly, the posterior gonopods in A. meridionalis possess very small angiocoxites, about the same size as the telopodital rudiments, the former bearing several setae, vs the angiocoxites by far outreaching the telopodital rudiments and being devoid of setae in A. aspromontis. Moreover, the presence/absence of setae on the angiocoxites is considered an important diagnostic character by Ćurčić et al. (2008), since these authors used it in their identifi cation key in several couplets concerning the species of Anamastigona. As regards A. halophila, it is not recognized as a valid species in the present study, although the unknown conformation of the posterior gonopods in the single known male leaves a certain amount of uncertainty about its possible synonymy with A. bilselii (Verhoeff, 1940).
The inner grouping of Anamastigona is currently almost completely unresolved, with the only recent consideration on the topic being that by Makarov et al. (2007), who divided the genus into two groups based on the presence/absence of telopodites on the posterior gonopods and the shape of their angiocoxites. According to their study, the Bulgarian endemics A. falcata (Gulička, 1967), A. alba (Strasser, 1960), A. lepenicae (Strasser, 1975) and A. delcevi (Strasser, 1973), possibly together with the Albanian A. albanensis Mauriès, Golovatch & Stoev, 1997, form a species group separate from the rest of their congeners. However, in such a division A. hauseri (Strasser, 1974) and A. pentelicona (Verhoeff, 1925) should also join the fi rst group, since their telopodites are completely reduced, with only some pigmented spots/granules indicating the position of the lost appendages, like the condition observed in Table 2. Main gonopodal characters of species of Anamastigona Silvestri, 1898. A. albanensis. On the other hand, unlike the Bulgarian species, which possess very slender, hornlike angiocoxites, the posterior gonopods in A. albanensis, A. hauseri and A. pentelicona are considerably less-strongly modifi ed. A strongly elongated shape of the angiocoxites is also present in A. bilselii (Verhoeff, 1940) and A. radmani Makarov et al., 2007, although they bear well-pronounced telopodital rudiments. The several main diagnostic gonopodal characters applied in the key by Ćurčić et al. (2008) and in the present one are of little help for any clear intrageneric division to be proposed. Most of the presumable derived characters (e.g., absence of telopodital rudiments on posterior gonopods or absence of setae on angiocoxites of anterior gonopods) are reductive in nature and thus likely to present homoplasies, rather than synapomorphies (see Table 2). A further diffi culty is the presence of unique, probably plesiomorphic characters in certain species, like the anterior gonopods possessing fl agella in A. matsakisi or telopodital rudiments in A. albanensis, both of these traits making it hard to compare them to the remaining congeners. Perhaps the most outstanding species of all is A. mauriesi: it displays a unique conformation of the posterior gonopods, which have unusually large colpocoxites and telopodital rudiments placed on top of the angiocoxites, the latter condition supposed to represent the most plesiomorphic state within the entire genus (Golovatch & Makarov 2011). On the other hand, the considerably enlarged angiocoxites in combination with the strongly reduced, knot-like telopodites may be the result of a different course of modifi cation of the posterior gonopods that might have taken place very early in the evolution of the genus. It is possible that future examination of vulval characters, which with very few exceptions are completely unknown in Anamastigona, could shed more light on the phylogenetic affi nities of its constituent species.
Anamastigona is surely more speciose than we presently know. This can be assumed from the small size of the animals, combined with their supposed low surface activity, as well as from the overwhelmingly local endemism. Vast, insuffi ciently explored areas like the Mediterranean coast of Turkey and, especially, the Caucasus, the latter considered as a diversity hotspot for the entire family Anthroleucosomatidae (Mauriès et al. 1997;Golovatch & Makarov 2011), are probably inhabited by a number of still undescribed members of the genus.