My old victorian tea cups & saucers

Hi I have this beautyful set of very old . I think they could be Victorian..? 4 tea cups & saucers they are blue & white I think they might be porcelain there very fragile on the back of them there is a crown and says Clematis. I can't work out if it says anything else. There in the dainty shape. I would like to know who made Thesa. I have been looking for a few years but I have had no luck. I have had them for 7 yrs & was left them from a loved one. If anyone knows anything about Thesa I would be so grateful. If you let me know .. Thanks.. traci