A new species of corophiid Amphipoda, Cheiriphotis trifurcata, collected from the seagrass bed of the Lower Gulf of Thailand, is described. Cheiriphotis trifurcata is characterized by its trifurcated tip of the modified setae on the outer ramus in male pleopod 3. In this paper, the new species is fully described and compared with related species and a complete key of the 16 valid species in the genus Cheiriphotis is given.

Two species of melitid amphipod were collected from the Gulf of Thailand. Dulichiella pattaniensis is new to science, and Melitalati latiflagella Ren & Andres, 2012 has not been previously reported from Thai Waters. Dulichiella pattaniensis is characterized by male gnathopod 2 distolateral crown with 4 spines; pleonite/urosomite formula 7-7-7-5-6-2; pereopod 5-7 dactylus with 2 accessory spines. This combination of characters has not been recorded previously in the Dulichiella. The characters of the specimens are described and illustrated. All specimens are deposited in the Princess Maha Chakri Sirindhorn Natural History Museum, Prince of Songkla University, Thailand.