Recently the Board of the Crown Prince's Affair of Japan was kind enough to send to the writer some living specimens of the fresh-water shrimps of Thailand. According to the information from the Board these shrimps were found from among the fresh-water fishes which had been carried back for studies by the Crown Prince on the occasion of his good will visit to Thailand near the end of the year 1964, and kept alive in his palace, but no other data are known.
The preliminary notice of examinations of the shrimps was presented by the writer himself at the meeting of the Chugoku-Shikoku Branch of the Japanese Zoological Society in 1965, and after that the further studies of them are carrying out by the writer. The shrimps from Thailand contain six specimens representing two species, of which one species belongs to the Atyidae and the other the Palaemonidae. The writer intends to describe them in detail herein after.