Abstract: This paper reports a new species: Synchaeta arcifera. arcifera. sp. nov.and tow records of China: Trichocerca marina (Daday, 1890),Anuraeopsis navicula Rousselet,1910. Type specimens are deposited in the Bioengineering College, Fujian Normal University.The new species with the following characteristics new to the taxonomy:1. Contracted specimens are of Crescent moon-shaped from lateral view.2. No foot and toe of these specimens can be observed whether living or in formalin. Latter part of body is of horn-shaped (or digenerate foot and toe?).3. Anus situated in the latter back of body.4. Uncus asymmetric,the right having 6 teeth and the left 7. Inner one of eachside—ginkgoleaf-shaped, remainders—sword-shaped.Remark:New species with stomach black-greenish or black-grownish and containing several black food vacuoles, the same case can be observed only in Ascomorpha of Gastropodidae, therefore the author suggests that new species is of close relation to Ascomorpha. Type specimens was collected from Mu-lan xi river (brackish water) Pu-tian city, Fujian province, China. Nov.20. 1993.