Camponotus crassus Mayr 1862: 670 Camponotus senex crassus Mayr Camponotus vezenyii Forel 1907b: 34 Camponotus crassus vezenyii Forel. Forel 1911b: 291 Camponotus ( Myrmobrachys ) crassus Mayr. Forel 1914a: 270 Camponotus ( Myrmobrachys ) crassus vezenyii Mayr. Forel 1914a: 271 Camponotus vezeni Forel. Emery 1920a: 260 Camponotus ( Myrmobrachys ) crassus var. picticornis Santschi 1936: 421 Camponotus vezenyii Forel. Kempf 1972: 54 Camponotus ( Myrmobrachys ) crassus var. picticornis Santschi. Kempf 1972: 51 A catalogue of the ants of Paraguay (Hymenoptera: Formicidae) Wild, Alexander L. Zootaxa 2007 1622 1 55 QDNS Mayr 1862 Mayr 1862 [151,505,474,498] Insecta Formicidae Camponotus Animalia Hymenoptera 46 47 Arthropoda species crassus    Camponotus crassusMayr 1862: 670. [w syntypesexamined, NHMW; Novara, Rio de Janeiro, Brazil].  Camponotus senexr.  crassusMayr: Forel 1879: 99.   Camponotus vezenyiiForel 1907b: 34. NEW SYNONYMY.[ holotypew examined, MHNG; Asunción, Paraguay(Vezényi)].   Camponotus crassussubsp.  vezenyiiForel. Forel 1911b: 291.   Camponotus( Myrmobrachys) crassusMayr. Forel 1914a: 270.   Camponotus( Myrmobrachys) crassusr.  vezenyiiMayr. Forel 1914a: 271.   Camponotus vezeniForel. Emery 1920a: 260.   Camponotus( Myrmobrachys) crassus var. picticornisSantschi 1936: 421. NEW SYNONYMY.  Camponotus vezenyiiForel. Kempf 1972: 54.   Camponotus( Myrmobrachys) crassus var. picticornisSantschi. Kempf 1972: 51.    Camponotus crassusis the most frequently recorded  Camponotusfrom Paraguay. This ant appears to be found in every terrestrial habitat typewith woody vegetation of sufficient diameter to house the arboreal nests in hollow twigs. The coloration of the antennal scapes shows slight variation among collections, from testaceous to dark reddish brown. The amount of pilosity on the mesosomal dorsum also varies somewhat. Forel’s typeof  C. vezenyiifrom Asunción is slightly more pilose and has lighter colored scapes than Mayr’s typeof  C. crassus, but it still falls well within the range of variation observed in Paraguayand is synonymized here. Santschi (1936) distinguished the variety  C. picticornisfrom  C. crassuson the basis of antennal scape color. I was unable to view Santschi’s typesof  C. picticornisfrom Loreto,  Argentina, but several other series from northern  Argentinaat NHMB identified by Santschi as  C. picticornisare within my conception of  C. crassus.