LONDON, July 18 (Reuters) - There are no FTSE 100 companies goingex-dividend on Thursday, although two British mid-cap companies are set to tradewithout entitlement to their latest dividend payouts. Among FTSE 250 companies going ex-dividend are: COMPANY (RIC) DIVIDEND (pence) GCP Infrastructure Investments Limited 1.9 SuperGroup 37 (Reporting by Kit Rees; Editing by Sudip Kar-Gupta)