Basal cell broad and irregular, somewhat pentagonal. Suprabasal cell also irregular, usually smaller than the basal, bearing distally a primary appendage and laterally secondary appendages on both sides. Primary appendage composed of a superposed series of cells, the two lower ones slightly longer than broad followed by much shorter and flattened cells, becoming disorganized at the tip in all specimens observed. Secondary receptacles quite elongate, variously recurved, terminating in an appendage like extension similar to the branches that arise from the two to five cells on both sides adjacent to the suprabasal. These branches more or less erect, composed of a linear series of about 10 subequal cells and terminating with a tuft of thin, hyaline, quite elongated branchlets and occasionally short, bottled-shaped antheridia. Stalk cell of the perithecium originating laterally from the basal cell of the branches, quite robust and usually short, subtending the unusually large basal cells of the perithecium. Perithecium regularly ovoid, not much broader than its basal cells, with a blunt, indistinguished apex. Total length of thallus from foot to tip of perithecium: 165-365 µm; perithecium: 105-170 x 50-60 µm; longest perithecial stalk cell: 135 µm; longest primary appendage: 70 µm; longest secondary receptacle branch: 150 µm; ascospores: 55 x 5 µm.

Basalis cellula compacta, inaequaliter pentagona. Suprabasalis cellula inaequalis, basali cellula minor, primam appendicem in summo ferens et utrimque secunda receptacula. Prima appendix e serie superpositarum cellularum constans, quarum duae inferiores parum longiores quam latiores, ceterae multo breviores. Secunda receptacula elongata, varie curvata, in tenues appendices desinentia. E cellulis secundorum receptaculorum exiles, erecti ramuli oriuntur caespitem tenuium, elongatarum appendicum et antheridia lagoenae instar in summo ferentes. Cellula stirpis perithecii valida ac brevis, a latere basalis cellulae ramulorum oriens. Perithecium ovatum, paulo latius quam magnae cellulae subjacentes, obtuso apice. Longitudo a pede usque ad apicem perithecii: 165-365 µm; perithecium: 105-170 x 50-60 µm; perithecii stipitis maxima longitudo: 135 µm; prima appendicis maxima longitudo: 70 µm; axes secondary: 150 µm; ascosporae: 55 x 5 µm.
Parasitus Macralymmae brevipennis et Omaliomimi conici in Nova Zelandia.
HOLOTYPUS: PDD 64943

ETYMOLOGY: referring to the habitat in which both host species were found.
NOTES: The new species is easily distinguished from the other 13 species in the genus Cucujomyces Speg. by the stout stalk and conspicuous basal cells of the perithecium. These characters can be found in a species of the closely related genus Balazucia R.K. Benj., i.e., Balazucia japonica Terada, which was also found on a member of the Staphylinidae (Terada 1980). The latter species, however, has a much more slender perithecium and a receptacle in which the suprabasal cell separates three obliquely superposed cells on both sides. The morphology and direction of growth of the secondary receptacles is also different. None of the previous species described in Cucujomyces have been found on Staphylinidae. The occurrence of the new species of Cucujomyces on two separate host species that share the same habitat lends further support to the hypothesis that transfer of ascospores between cohabiting hosts is frequently encountered in nature.

HOLOTYPE: NEW ZEALAND, South Island, Invercargill, Oreti Beach, on the metasternum of Omaliomimus conicus (Fauvel) (Coleoptera: Staphylinidae: Omaliinae) taken under kelp, 25 Jan. 1984, leg. P.M. Hammond, det. M.K. Thayer (PDD 64943).
ISOTYPE: NEW ZEALAND, South Island, Invercargill, Oreti Beach, on the abdomen and metasternum of Omaliomimus conicus taken under kelp, 25 Jan. 1984, leg. P.M. Hammond, det. M.K. Thayer (AW-573); same data on elytra (AW-573).
PARATYPE: NEW ZEALAND, South Island, Invercargill, Oreti Beach, on the abdomen of Macralymma brevipenne Cameron (Coleoptera: Staphylinidae: Omaliinae), leg. P.M. Hammond (AW-574).