- Khlung (ขลุง)
- Thung Yai (ทุ่งใหญ่), which is now Khao Saming district.
Now, the interesting thing is to compare this with the book "The Provincial Administration of Siam" by Tej Bunnag, still my prime source of the administrative system 1892-1915. In appendix II it has a list of all provinces in the various Monthon, yet for Chanthaburi it only lists Rayong, Chanthaburi and Trat. The text on page 163 gives only few further facts on this Monthon.
In 1906 monthon Chanthaburi was created when France returned the province which she had occupied since 1893. In 1907, Trat, the south-easternmost province which the French had occupied since 1904, was joined to monthon Chanthaburi.I wasn't yet able to find an announcement in the Royal Gazette on the integration of Mueang Trat into Monthon Chanthaburi, which must have taken place only shortly before the abolishing on Mueang Khlung.