Balachowsky, 1954
Appearance in life
Scale cover of adult female mussel shell-shaped and slightly irregular, flat, white and pearly or silky in appearance, with yellow, terminal exuviae. Scale cover of immature male different from that of female; small and elongated, white, felted, tricarinate, with terminal exuviae.
Morphology
Adult female not pupillarial; body elongate-fusiform, widest at metathorax, then tapering to apex of pygidium. Derm membranous except for pygidium; mesothorax, metathorax and free abdominal segments moderately produced laterally, without marginal sclerotized spurs. Pygidium shallow and rounded, the median posterior edge almost horizontal, with a shallow median notch. Median lobes non-zygotic, strongly divergent and quite widely spaced, with distinct marginal setae between the bases; variable in size and prominence (and the depth of the notch between them); each lobe with inner margin oblique, longer than the outer; lobe wider than long, with a finely to coarsely serrate tip. Second lobes usually smaller than median lobes, also varying in size; either bilobed, with the inner lobe larger and rounded and the outer lobe small and conical, or reduced to a single, small rounded lobe. Third lobes absent in specimens with small lobes, but in specimens with well-developed lobes, small bilobed third lobes may be present. Ventral paraphyses absent. Gland spines small, absent from between the median lobes; present singly on either side of other pygidial segments. Anus circular, usually situated near anterior 1/4 of pygidium; vulva situated near anterior 1/3 of pygidium. Marginal macroducts only slightly larger than dorsal ducts, each sclerotized around the orifice, with the long axis of the orifice often intermediate between parallel and perpendicular to the margin; sometimes associated with pore prominences or marginal serrations; never numbering more than 3 on segments VI and VII on either side of the pygidium; absent from between median lobes. Some dorsal macroducts on pygidium as large as marginal ducts, with sclerotized rims, others (further anteriorly) rather smaller and not sclerotized; absent submarginally from abdominal segments VI and VII. Dorsal macroducts present in segmental rows or series of submarginal and submedian ducts, from mesothorax to submedian part of segment VI, but absent from segments VII or VIII; segments II-V with two rows of submarginal ducts on either side. Ventral conical duct tubercles present submarginally anterior to abdominal segment IV. Perivulvar pores quite numerous, present in 5 groups. Stigmatic disc pores few, present by anterior spiracle only. Antennae with a few microducts scattered about their bases; bases situated fairly close together, each bearing 2 setae very close together.