Hippomenella Canu and Bassler, 1917

Arakawa, Shinji, 2024, Descriptions of Three Cheilostomatid Bryozoan Species from the Continental Shelf off Boso Peninsula, Japan, Species Diversity 29 (1), pp. 99-110 : 103-104

Genus Hippomenella Canu and Bassler, 1917

Diagnosis. Colony encrusting. Frontal shield imperforate in suboral area, with umbonuloid component and two or more rows of areolar pores. Orifice horseshoe-shaped, round- ed distally, with weakly concave proximal border and lateral condyles. Oral spines and adventitious avicularia present. Ovicell with partly pitted endooecium. (see Berning 2013).

Type species. Lepralia mucronelliformis Waters, 1899 .

Remarks. The concept of this genus has been unclear since the type species does not coincide with the original generic diagnosis given by Canu and Bassler (1917). These authors considered Hippomenella to have laterally or proximally directed avicularia and “lateral crescentic areas” on the ovicell ( Canu and Bassler 1929), but this feature of the ooecium was not based on the type species. The ovicell in the lectotype of H. mucronelliformis was not fenestrate but partly pitted ( Brown 1949; Berning 2013).

As pointed out by Berning (2013), it must be discussed whether species with pseudopores on the ovicell, such as H. vellicata (Hutton, 1873) , should be included in this genus. Based on a recent molecular analysis by Orr et al. (2022), H. vellicata is closely related to the genus Escharoides Milne Edwards, 1836 , but H. mucronelliformis was not included in the material for their analysis. The relationship between a pitted ooecium and ooecial pseudopores also has not been elucidated.

Furthermore, the family affiliation of Hippomenella is presently unclear. Berning (2013) placed it in Romancheinidae based on its resemblance to Escharoides , but no species in Romancheina Jullien, 1888 was included in molecular analysis by Orr et al. (2022).