Habit short and compact, erect. Basal cell of receptacle small, 15 x 12 µm, ovoid, with peculiar brown dendritic striae, giving way distailly to cells II and VI which lie side by side. These two cells subequal, 20 x 12-15 µm, broadly rectangular. Cell II superposed by cell III, which is slightly longer than broad, 15 - 12 µm, the latter giving way distally to a single (occasionally two) appendage cell that cuts off small, triangular corner cells from both upper angles, which produce a dense tuft of terminal phialides (and intercalary antheridia?). Secondary stalk cell of perithecium (VII), 20 x 12 pin, similar in size to, or slightly larger than VI, giving way distally to the perithecial basal cells, which are isodiametric and well defined. Perithecium subelliptical, more or less erect, the venter, neck, and tip region not well distinguished, gently tapering to the short, broad, subtruncate apex that bears two minute apical teeth. Perithecium with four outer wall cells in each vertical row. Total length of thallus from foot to tip of perithecium: 115-145 µm; perithecium: 70-85 x 35 -40 µm; longest primary appendage: 55 µm; ascospores not observed.

Fungus parvus ac compactus. Receptaculi basalis cellula parva, 15 x 12 µm, ovata, fuscis striis praedita, cellulas II et VI, subequales, 20 x 12-15 µm, fere rectangulas et totas adhaerentes, sustinens. Cellula III supra II posita, paulo longior quam latior, 15 x 12 µm, appendicem sustinens. Appendix constat ex una (raro duabus) magna cellula, quae in superioribus angulis duas parvas, fere triangulas cellulas fert, crebrum caespitem phialidum gignentes. Cellula VII cellula VI similis, 20 x 12 µm, perithecii basales fere quadriangula cellulas sustinens. Perithecium fere ellipticum, in subtruncatum apicem desinens, in summo duobus minimis dentibus praeditum. Longitudo a pede usque ad apicem perithecii: 115-145 µm; perithecium: 70-85 x 35-40 µm; prima appendicis maxima longitudo: 55 µm; ascosporae non observatum. Parasitus Sephedophili niticollis in Nova Zelandia. HOLOTYPUS: PDD 64946

ETYMOLOGY: referring to the brush-like termination of the primary appendage.
NOTES: Although bearing more than a superficial resemblance to species of Corethromyces, the new species undoubtedly belongs to the recently segregated genus Diphymyces I.I. Tav. (Tavares 1985). Diagnostic characters of the latter genus are the relative positions of cells II and VI that lie side by side and are separated by a vertical septum, the small apical outgrowths at the apex of the perithecium and the four tiers of perithecial wall cells. There are presently six known species in the genus Diphymyces, five of which were originally described in Corethromyces. All of these six species have been found on beetles belonging to the families Catopidae and Colonidae. The new species differs from Diphymyces appendiculatus (Thaxt.) I.I. Tav., Diphymyces bidentatus (Thaxt.) I.I. Tav., Diphymyces niger (T. Majewski) I.I. Tav., Diphymyces silphidarum (Thaxt.) I.I. Tav., and the recently described Diphymyces urbasoli Santµm. (Santamaria 1993) in perithecial and appendage details and is perhaps most closely allied to Diphymyces curvatus (Thaxt.) I.I. Tav., which was also described from New Zealand. Diphymyces penicillifer differs from the latter essentially in possessing a much shorter appendage (55 µm long compared with 75-100 µm) with the cluster of terminally produced phialides much more compact and brushlike (hence the specific epithet), and the perithecium more straight and erect. This is also the first member of the genus to be found on a staphylinid beetle.

HOLOTYPE: NEW ZEALAND, North Island, Wellington, north of Upper Hutt, Akatarawa Saddle, el. ca. 700 m, on the abdomen of Stenomalium helmsi (Cameron) (Coleoptera, Staphylinidae, Omaliinae), taken in litter, 17 January 1983, leg. P.M. Hammond (PDD 64946).
ISOTYPE: Same data (AW-677).