This interesting genus of gigantic Scydmaenidae was described by Laporte, comte de Castelnau, in the Ann. Soc. Entom. de France, 1832, p. 396, and based on the first known species Clidicus grandis) the same species has been figured in the Atlas of the Genera des Coléoptères of Lacordaire, tab. 16, fig. 4, and Fairmaire (Ann. Soc. Ent. de France, 1856, p. 317) added some complementary remarks to its description. In 1863 Pascoe (Journ. of Entomology, II, p. 28, plate II, fig. 3) described a second species as Cl. formicarius. A third species, Cl. taphrocephalus, was added by Gestro in 1878 in the Ann. Mus. Civ. Genova (XII, p. 144). The Clidicus Doriae, described by Schaufuss in the Ann. Mus. Civ. Genova, 1884 [(2) I, p. 419], does not differ essentially from formicarius according to Reitter (Wien. Entom. Ztg. 1887, p. 64). Reitter himself described (loco citato) a supposed new species of Clidicus name of Ganglbaueri; under the but this description was founded upon a mistake, corrected by Reitter on p. 303 of the same volume; the species, which Reitter supposed to be Cl. grandis Casteln. proved to be taphrocephalus Gestro, and Ganglbaueri Reitter is certainly grandis of Castelnau, as the latter author has described as grandis a species with triangular, highly bituberculated head. Nevertheless I think, we must consider Cl. Ganglbaueri not simply synonymous with grandis Cast., because the specimen in the Hofmuseum of Vienna, which Reitter has described as Ganglbaueri, belongs to a form of grandis with smaller, not perfectly rounded thorax, which I find also among the grants-specimens of the Museum of Leyden and which must be considered as a variety of grandis, whose typical form has a larger, perfectly globose thorax. Perhaps it will be proved later, that this difference is only of sexual or individual character; but meanwhile it will be safer to retain Ganglbaueri as a variety of grandis. Finally I found in the collection of the Leyden Museum a specimen named (but not described) as villosulus Vollenh., which is identical with formicarius Pasc.