The strain was isolate in 1966 from a house mouse (Mus musculus) in Roumania by a work ing group of the Institute of Hygiene in Iasi (Nicolescu, 1976). In this paper the serovar name iassy is used although in the same paper there is a table summarising the results of factor analysis carried out by Kmety (submitted by correspondence) in which the name roumanica is given. The first complete valid description including the serovar name roumanica was given only in 1977 when Kmety published his results of his factor analysis studies of the Hebdomadis serogroup. Since this is considered as the first valid description, the serovar name roumanica with reference strain LM 294 has been accepted by the TSC (Manchester, 1986). In this paper Kmety suggests to place the serovar in the subgroup Wolffi of the newly established serogroup Sejroe.