Arachnologische Mitteilungen 55

Male dimorphism in Linyphiidae 53 cristata , but the very different form of the caput and its cleft …will distinguish it at once”. Later, Simon (1884, 1926) also gave considerable impor- tance to the shape of cephalic lobes in describing several (sub) species in the genus Prosoponcus : P. bicephalus Simon, 1884, P. rectilobus Simon, 1884 an P. thyrsiger Simon, 1884. None of these species was matched to a female, except for P. bicephalus bicephalus ; yet the female of the latter species appeared to be that of Dicymbium nigrum (Blackwall, 1834). Denis (1948) added one more species to this species group, D. arvernus , from France, Auvergne. He stated that this species was close- ly related to D. foraminifer , but slightly differed in the shape of cephalic lobe. Georgescu (1969) was the first author to propose that D. cristatus , D. foraminifer , D. bicephalus , D. rectilobus and D. thyr­ siger all belong to the same species, occurring in two morphs: cristatus and foraminifer. She also included Diplocephalus cras­ silobus (Simon, 1884) in that list, but the conformation of the male palp of the latter species is completely different (cf.,Mil- lidge 1979, Pesarini 1996). The suggestion by Georgescu has not been followed and in the World Spider Catalog (2018), these names are currently listed as separate species. We have been able to re-examine the material of all these Diplocephalus species, including the types of D. bicephalus and D. rectilobus , and can confirm Georgescu’s proposal. Fig. 1: a-c. Diplocephalus cristatus (Blackwall, 1833) (Belgium), d-f. D. rectilobus (Simon, 1884) (the holo- type), g-i. D. foraminifer (O. Pickard- Cambridge, 1875) (Greece), j-l. D. bice- phalus (Simon, 1884) (the lectotype), m, o: D. arvernus Denis, 1948 (from Denis 1948, figs 1-8); n. D. foraminifer (O. Pickard-Cambridge, 1875) (from Deltshev, 1985, fig. 7); a, d, j, m. Male prosoma, lateral view; b, e, h, k, n. Male palp, lateral view; c, f, i, l, o. Male palpal tibia, dorsal view.