Genus Xianguangia Chen & Erdtmann, 1991

Type species. Xianguangia sinica Chen & Erdtmann, 1991

Diagnosis. As for the type and only species.

Remarks. The different architecture of the calyx separates Xianguangia from Daihua and Dinomischus (Table 1). Xianguangia only possesses an invaginated pit in the basal portion of the calyx, whereas the latter two taxa have either a blunt tip or a slender stalk, respectively (Zhao et al., 2019). The oral surface expands to various degrees among these three taxa, forming three oral domes with slender bracts in Daihua, and an elongated oral cone in Dinomischus (Zhao et al., 2019) . Xianguangia shares with Daihua and Dinomischus an outer sheath enveloping each tentacle rod. A single sheath has been identified in Xianguangia and Dinomischus, while two possible paired sheaths have been suggested in Daihua (Zhao et al., 2019) .