<br> The Camponotus subgenus Myrmosagasubgen. rev. from the Malagasy region is revised based on analysis of both qualitative morphological characters and morphometric traits. The multivariate analysis used the Nest Centroid (NC)-clustering method to generate species hypotheses based on 19 continuous morphological traits of minor workers. The proposed species hypotheses were confirmed by cumulative Linear Discriminant Analysis (LDA). Morphometric ratios for the subsets of minor and major workers were used in species descriptions and redefinitions. The present study places the subgenus Myrmopytiasyn. nov. in synonymy to Myrmosaga. It recognizes 38 species, of which 19 are newly described: C. ainasp. nov., C. arosp. nov., C. asarasp. nov., C. atimosp. nov., C. bemahevasp. nov., C. bozakasp. nov., C. darainasp. nov., C. harenarumsp. nov., C. joanysp. nov., C. karstisp. nov., C. kelimasosp. nov., C. lokobesp. nov., C. mahafalysp. nov., C. niavosp. nov., C. rotraesp. nov., C. sambiranoensissp. nov., C. tapiasp. nov., C. tendryisp. nov., C. vanosp. nov. Eleven species are redescribed: C. aurosus Roger, C. cervicalis Roger, C. dufouri Forel, C. gibber Forel, C. hagensii Forel, C. hova Forel, C. hovahovoides Forel, C. immaculatus Forel, C. quadrimaculatus Forel, C. roeseli Forel, C. strangulatus Santschi. The following are raised to species and redescribed: C. becki Santschi stat. nov., C. boivini Forel stat. rev., C. cemeryi Özdikmen stat. rev., C. mixtellus Forel stat. nov., C. radamae Forel stat. nov.Camponotus maculatus st. fairmairei Santschi syn. nov., is synonymized under C. boivini. The following are synonymized under C. cervicalis: Camponotus cervicalis gaullei Santschi, syn. nov.; Camponotus perroti Forel, syn. nov.; Camponotus perroti aeschylus Forel, syn. nov.; Camponotus gerberti Donisthorpe, syn. nov.Camponotus dufouri imerinensis Forel, syn. nov. is a synonym of C. dufouri, Camponotus hova var. obscuratus Emery, syn. nov. is a synonym of C. hova, Camponotus quadrimaculatus opacata Emery, syn. nov. is a synonym of C. immaculatus, Camponotus maculatus st. legionarium Santschi, syn. nov. is a synonym of C. roeseli, Camponotus hova maculatoides Emery, syn. nov. is a synonym of C. strangulatus. The following are synonymized under C. quadrimaculatus: Camponotus kelleri Forel, syn. nov., Camponotus kelleri var. invalidus Forel, syn. nov., Camponotus quadrimaculatus sellaris Emery, syn. nov. As C. imitator Forel, C. liandia Rakotonirina &amp; Fisher, and C. lubbocki Forel have been recently described and redescribed, only diagnoses and taxonomic discussions are provided. This revision also includes an illustrated species identification key, taxonomic discussions, images, and distribution maps for each species superimposed on the ecoregions of Madagascar.
