Monographis phuquocensis, Huynh, 2018

Huynh, Cuong, 2018, Two new species of penicillate millipedes (Diplopoda, Polyxenidae) from Phu Quoc Island in southern Vietnam, Zootaxa 4402 (2), pp. 283-302 : 299-300

Comparison of Monographis phuquocensis sp. n. to other species in the genus Monographis

The genus Monographis is divided into 2 groups depending on the arrangement of the sensilla on the antennal article VI, forming either a crescent or a triangular shape ( Huynh and Veenstra, 2015). M. phuquocensis sp. n. belongs to the group where the sensilla are arranged in a crescent-shape, as does M. kraepelini , M. annandalei , M. baihualingensis , M. demangei and M. mira . These species can be distinguished by characteristics of the labrum and telotarsus. M. phuquocensis sp. n. has a labrum with a smooth, asetose surface which differs from M. kraepelini , M. baihualingensis and M. demangei . Setae on the anterior margin of the lamellae of M. phuquocensis sp. n. are slender compared to those of M. kraepelini , which are acute triangular shaped setae ( Nguyen Duy-Jacquemin and Condé, 1967). Despite the similarity in the arrangement of the sensilla on the 6th antennal article between M. phuquocensis sp. n. and M. demangei , the telotarsus structure is distinctly different in these 2 species. The anterior setiform process from the telotarsus of M. phuquocensis sp. n. is half the length of the claw, which contrasts with M. demangei where the anterior setiform process is longer than the claw.

Remarks. Monographis phuquocensis sp. n. has the characteristics of a group of Monographis species with the sensilla forming a crescent shape on the antennal article VI and a row of slender setae being present on the anterior margin of the labrum. The similarity of characteristics observed in M. phuquocensis sp. n., M. kraepelini , M. baihualingensis and M. demangei makes it challenging to distinguish between these species. M. phuquocensis sp. n. has a distinctive character on the surface of the labrum with the presence of slender setae on the anterior margin of the labrum and the structure of telotarsus. These characters can be used to distinguish this species from all the known species from genus Monographis .