Myrmecium Latreille, 1824

Marusik, Yuri M., Omelko, Mikhail M. & Koponen, Seppo, 2015, A redescription of the ant mimicking spider Myrmecium gounellei (Araneae: Corinnidae, Castianeirinae), with notes on the genus, Zootaxa 3985 (2), pp. 296-300 : 296-297

Myrmecium Latreille, 1824

Type species M. rufum Latreille, 1824 from Brazil (by monotypy).

Note. Myrmecium is the oldest genus name in the Corinnidae , described 16 years earlier than Corinna C.L. Koch, 1841 .

Diagnosis. Myrmecium is similar to Sphecotypus O.P.-Cambridge, 1895, a genus known from the Neotropics and Southeast Asia, in having deep constrictions on a narrowed carapace, but can be easily distinguished from this genus and other Castianeirinae by having three deep prosomal constrictions (one between coxae II and III, one between III and IV, and one less marked behind the coxa IV) ( Figs 1, 6 ), a separation between coxae III and IV more than twice width of the coxa III, and sternum projected between coxae IV ( Fig. 2 ). Furthermore, Myrmecium significantly differs from similar genera by its short abdominal scutum and lack of an inframammillary scutum ( Figs 4, 5, 7 ), in addition to almost touching coxae I and II ( Fig. 2 ).

Comments. Judging from the illustrations of the habitus and male palp of M. itatiaiae Mello-Leitão, 1932 , the latter could be a junior synonym of M. rufum (cf. Figs 9–13 ).

Figures

FIGURES 1 – 7. Somatic characters of Myrmecium gounellei, female (1 – 5) and male (6 – 7). 1, 6 habitus, dorsal; 2 prosoma and petiolus, ventral; 3 prosoma, lateral; 4 abdomen, lateral; 5, 7 abdomen, dorsal. Abbreviation: Ds dorsal scutum, Es epigastric scutum, Mp mating plug.

FIGURES 8 – 15. Original illustrations of several Myrmecium species showing habitus and copulatory organs. 8 M. obscurum (habitus, epigyne and palp); 9, 11 male of M. itatiaiae (habitus and palp); 10 M. rufum (habitus, epigyne and palp); 12 M. rufum (bulb and cymbium); 13 M. rufum (male palpal tibia, retrolateral); 14 – 15 habitus of M. bifasciatus and M. gounellei respectively. Figs 8, 10 after Keyserling (1891); 9, 11 after Mello-Leitão (1932); 12 – 13 after Camargo (1953); 14 after Taczanowski (1874); 15 after Simon (1896).