Genus Cantharomyces Thaxt.

MB#792

Proceedings of the American Academy of Arts and Sciences 25: 9 (Thaxter 1890). –

Type species: C. bledii Thaxt.

Brief description

Monoecious. Receptacle three-celled, with the three cells (I, II and III) superposed and separated by ± horizontal septa. Primary appendage consisting of a basal cell which divides to form a compound antheridium and a few to many sterile cells. Above, the appendage may be simple to variably branched. Antheridium consisting of several irregularly arranged cells; the discharging pore is lateral. Perithecium with 4–5 cells in each vertical row of outer wall cells.

Remarks

The genus consists of 29 species, of which 13 are known in Europe, eight in Denmark. The most recently described species are C. elongatus (Haelewaters & De Kesel 2013) and C. paschalis W.Rossi & Santam. (Haelewaters et al. 2021) . The genus is well-characterized by the compound antheridium which occupies part of the appendage basal cell (Fig. 75F, an).

Key to the Danish species (partially following Majewski 1994b and Santamaria 2003)

1. Cell II almost entirely blackened...................................................................................................... 2

– Cell II not so blackened, although some pigment, darkening or black spots may be present .......... 3

2. Antheridium lateral on the appendage basal cell, which is narrower than cell III. Appendage unbranched. On Dryops (Col. Dryopidae)......................................................... C. denigratus Thaxt.

– Antheridium occupying most of the appendage basal cell, which is almost spherical and broader than cell III. Appendage branched above the basal cell. On Thinodromus Kraatz, 1857 (Col. Staphylinidae Oxytelinae) ......................................................................................................... C. numidicus Maire

3. Primary appendage unbranched........................................................................................................ 4

– Primary appendage ± branched......................................................................................................... 5

4. Appendage basal cell, including antheridium, elongated, narrow. On Dryops (Col. Dryopidae) ....... .................................................................................................................................. C. italicus Speg.

– Appendage basal cell, including antheridium, rounded or convex distally, broader than long. On Syntomium Curtis, 1828 (Col. Staphylinidae Oxytelinae)............ C. elongatus Haelew. & De Kesel

5. Antheridium occupying the middle side of appendage basal cell, without contacting upper and lower septa. On Platystethus Mannerheim, 1830 (Col. Staphylinidae Oxytelinae) ..... C. platystethi Thaxt.

– Antheridium occupying the corner or a lateral of the appendage basal cell, reaching either the upper and/or the lower septa....................................................................................................................... 6

6. One to three cells above the appendage basal cell strongly flattened, inflated, separated by constricted and slightly darkened septa. On Aploderus Stephens, 1833 (Col. Staphylinidae Oxytelinae) .......................................................................................................... C. aploderi Huldén

– Otherwise.......................................................................................................................................... 7

7. Cell III longer than broad. Appendage basal cell showing a papilla on the upper-inner corner, which probably represents an efferent neck. Cell VI elongate and strongly narrowing towards the basal portion. On Bledius (Col. Staphylinidae Oxytelinae)......................... C. papillatus Santam. sp. nov.

– Cell III broader than long. Appendage basal cell without papilla. Cell VI not as above. Usually on Trogophloeus Mannerheim, 1831 and allied genera (Col. Staphylinidae Oxytelinae)........................ .............................................................................................................................. C. orientalis Speg.