Diagnosis of new species: Small to medium size, pear-shaped marine Homalogastra in vivo ca. 25 - 35 μm ×12 - 20 μm, with 2 macronuclear segments; contractile vacuole opening at the end of the 2nd kinety, caudal cilium often connected with a thread of mucus, with which the animals attach themselves to detritus; ca. 16 somatic kineties; direct as well as check-like indirect silverline system typical of the genus, the basal-body-complex opens into the posterior circular fibril between meridians 8 and 9.

Remarks: As compared with its closely related species, H. filificum (KAHL, 1931) nov. comb., the new species is characterized by the following peculiarities; 1) it always has two macronuclear segments, and 2) the location of the last meridional silverline (SKn) at the posterior end, which passes across the caudal pole and joins the circular fibril between kinetics 8 and 9 but not between 11 and 12 (Fig. 4).

Type specmens: One slide of holotype specimens and 4 slides of paratype specimens are deposited in the Laboratory of Protozoology, College of Fisheries, Ocean University of Qingdao.

Behaviour and ecology: In fresh collections and in cultures the animals tend to swim near the bottom of the dish and are, occasionally, suspended in great abundance in the water. On the bottom animals are often connected by a fine thread (through the caudal cilium) with the detritus and like that of H. filificum, revolving about the point of attachment. The species was collected from a marine shrimp farming pond in Weifang on the Bohai coast. Ecological characters: salinity about 24, pH 7.8 - 8.0, water temperature 19 - 22°C.

By lack of feature “rear left l/4 of body unci1iated”, the genus Urocyclon Small & Lynn 1985 should be considered as a junior synonym of Hamalogastra, Hence, two new combinations can be established: H. filificum (formerly Urocyclon filificum = Uronema filificum, KA-HL, 1931) nov. comb., H. chesapeakensis (formerly Urocyclon chesapeakensis, Small & Lynn 1985) nov. comb..