The meiotic and mitotic chromosomes of the five recognized species ofSolatopupaPilsbry 1917 are described and compared. Meiosis is of a standard type. The karyotype ofS. psarolena(Bourguignat) with 2n=56 chromosomes and a conspicuously large metacentric pair is compared with those ofS.pallida(Rossmässler) andS.simonettae(Giusti) having 2n=58 chromosomes, and with that ofS.similis(Bruguière) which has 2n=60. A Robertsonian fusion could be linked with the splitting ofS.psarolenafrom a common ancestor with the congeneric species. The diploid value 2n=58 is most probably the ancestral one.