Pyrgeuma Shear

Shear, William A., 2012, Pyrgeuma pyrgodesmoides, n. gen., n. sp., a new millipede from Malaysia with unusual surface structures (Diplopoda, Chordeumatida, Heterochordeumatidae), Zootaxa 3560, pp. 79-86 : 80

Pyrgeuma Shear , new genus

Type species: Pyrgeuma pyrgodesmoides Shear , n. sp.

Diagnosis: Males of this genus, like Infulathrix males, have 30 rings, compared to the 32 rings of Heterochordeuma species males (females of all heterochordeumatids have 32 rings). Unlike species of Heterochordeuma , the anterior gonopods do not pass lateral and posterior to the posterior gonopod colpocoxites, and unlike Infulathrix siam Shear 2000 , the male tenth coxae are not conspicuously enlarged and modified, nor are the third male femora enlarged. The integument of at least some species of heterochordeumatids appears slightly roughened, or velvety, due to small microtrichia. In Pyrgeuma, these microtrichia are larger, curved and spatulate, and give the dorsal surface a coarsely rough appearance. Beginning on the first segment after the collum, the metazonites bear a pair of elevations that become more prominent posteriorly. The six metazonital setae characteristic of chordeumatidans are not detectable at dissecting microscope magnification; they are no larger than the exaggerated microtrichia on midbody segments. Under the scanning electron microscope (SEM) they can be seen to be blunt, with 5–7 prominent longitudinal ridges. Further details are given in the description below of the single known species.

Etymology: The name of the genus (neuter) draws attention to the resemblance of the species to pyrgodesmid polydesmidans.