Two new species of Pratinus Attems, with taxonomic notes on the genus and a redescription of its type-species (Diplopoda, Polydesmida)

Recently, in my paper on the Paradoxosomatidae of Borneo (JEEKEL, 1963), I discussed the taxonomy of the genus Pratinus Attems, 1937, and showed that the species of this genus in the wide sense as conceived by ATTEMS (1937, 1953) in majority belong to three other genera, viz., Orthomorpha Bollman, 1893, Leiozonius Jeekel, 1963, and Gigantomorpha Jeekel, 1963. Pratinus itself was restricted to a concept largely conforming to the idea held by POCOCK when he established this genus under the preoccupied name of Prionopeltis in 1895. Furthermore, attention was drawn to the fact that the two species of Euphyodesmus Attems, 1931, described from Ceylon, for which CHAMBERLIN (1941) created a separate subgenus Ceylonesmus, actually belong to Pratinus. In recapitulation, Pratinus was emended to embrace the following species: P. planatus (Poc., 1895), P. taurinus (Poc., 1895), P. cervinus (Poc., 1895), P. greeni (Att., 1936), and P. vector (Chamb., 1941). A re-examination of the type-species of the genus, P. cervinus, the study of the two new species described in the present paper, and a review of the pertinent literature now has convinced me that the concept of Pratinus must still undergo a slight alteration to the effect that the Indochinese species which ATTEMS (1937, 1953) described in the genus Centrodesmus Pocock, 1894, should be reallocated in Pratinus. The type-species of Centrodesmus, C. typicus Pocock, 1894, from Sumatra is known only in the female sex. The other Sumatran species, C. discrepans Silvestri, 1895, also was based on a female. As regards the development of the lateral keels, these species bear a certain resemblance to some species of Pratinus and some of the Indochinese species which ATTEMS referred to Centrodesmus. However, such a similarity might as well be a case of evolutionary parallelism and not necessarily signifies congenerity. Moreover, POCOCK already considered the species of Pratinus generically distinct from Centrodesmus, and since he is probably still the only one who has seen the type-species of both genera, it seems better to follow tentatively his usually sound opinion. At any rate, the species referred to Centrodesmus by ATTEMS, on account of their gonopod structure cannot be kept separate from Pratinus.