Reussinella

Gordon, Dennis P., 2009, New names for some bryozoan homonyms, Zootaxa 2133, pp. 64-68 : 66-67

Reussinella nom. nov.

Gender: feminine.

Diagnosis. Colony encrusting, unilaminar, multiserial. Zooids with an extensive granular cryptocyst, somewhat convex except for area proximal to orifice, with sparse marginal foramina. Gymnocyst vestigial, represented by exceedingly thin marginal strip interzooidally. Opesia small, roundly triangular, the operculum smaller than the opesia but of the same length and parallel-sided. A pair of very short oral spines present, with cuticularised bases, retained in ovicelled zooids. No avicularia. Ovicell subimmersed in cryptocyst of originating zooid but frontally prominent, surface granular and transversely ridged, not closed by zooidal operculum. Interzooidal communication via basal pore-chambers.

Remarks. The family attribution of this genus is not straightforward. Kluge (1922) conservatively included Reussina in the Membraniporidae as traditionally circumscribed, part of which would today correspond to the Calloporidae . In parallel, Taylor & McKinney (2006) provisionally included Euritina , to which Osburn (1950) attributed the type species, in the Calloporidae [cf. Bassler (1934), who included Euritina in the Alderinidae , a family considered synonymous with Calloporidae ]; Euritina species have much larger opesiae than in R. arctica and thus can compared with calloporid genera like Amphiblestrum . On the other hand, related calloporid genera like Ammatophora and Rhamphonotus have smaller opesiae and indeed bear comparison with Reussinella arctica . Osburn (1950), on the other hand, included the species in the microporoidean family Aspidostomatidae , and indeed there are a number of morphological similarities. On balance, Reussinella is here provisionally included in the Microporidae . Not only is the opesia small (though not yet fully corresponding to the orifice/operculum in size, but the sparse marginal pores ― unknown in calloporids and aspidostomatids ― appear to be opesiules. They were not noted by previous workers.