Chromosome analysis ofMuscina stabulanswith Giemsa and silver nitrate staining and C-banding revealed an example of an exception among Muscidae.M. stabulansalso presents the diploid chromosomal set consisting of 10 biarmed chromosomes, being 4 pairs metacentric and one pair submetacentric. None of the pairs was found heteromorphic. Positive but small C-band regions were always located on the centromeric regions of all chromosomes; an intersticial C + band appears only on the short arm of chromosome 2. In meiotic plates only chromosome 2 was observed bearing one Ag-NOR site on the short arm too.