Aeolidiella Bergh, 1867

Miller, M. C., 2001, Aeolid nudibranchs (Gastropoda: Opisthobranchia) of the family Aeolidiidae from New Zealand waters, Journal of Natural History 35 (5), pp. 629-662 : 646

Genus Aeolidiella Bergh, 1867

Aeolidiella Bergh, 1867: 99 ; Bergh, 1874: 738 ±739; Bergh, 1892: 1019; Eliot, 1910: 174; VayssieÁre, 1913: 299±300; Engel 1925: 4 ±10; Odhner, 1939: 53, 81±85; Pruvot-Fol, 1954: 425 (as Eolidina Quatrefages, 1843 ); Marcus, 1961: 55; Tardy, 1969: 33 ±35; Schmekel and Portmann, 1982: 223; Thompson and Brown, 1984: 159. (Placed on the O cial List of generic names in Zoology, see Lemche, 1964b and I.C.Z.N., 1966b).

Diagnosis

Body wide, rhinophores short, stout, simple or with lamellae, many thin or a few thick; cerata fusiform to cylindrical, occasionally slightly ¯attened, arranged in rows running ventrally and anteriorly, separated mid-dorsally anteriorly leaving a clear area, posteriorly completely covering back; rows single or double at lower end, ®rst two lateral ducts of digestive gland arches, rest single tubes; anus and abanal renal pore immediately posterior to second arch, i.e., fourth ceratal row, anus near upper end of interceratal space, renal pore near or at lower end, reproductive apertures below middle of ®rst arch; foot broad, shallowly curved anteriorly, extending laterally as tentacular processes, tail short and pointed: oral glands very large, cylindrical, widest close to proximal (blind) end; radular teeth fairly broad, distinctly bilobed, medium notch with large cusp, notch may be wide with uniform denticles; jaw masticatory process smooth.

Type species. Aeolidiella soemmeringi (Leuckart, 1828) , Bergh, 1867, non Leuckart (5 A. alderi (Cocks, 1852)) , by subsequent designation ( Suter, 1913).

In external form the members of this genus parallel Aeolidia papillosa (L.) in being generally very wide bodied and having the anus behind the ®rst post-cardiac group of cerata. However, they are distinct in the cerata being fusiform or only slightly compressed, and arranged in distinct rows (even though the lateral branches of the digestive gland are arched). Though the anterior rows in some Aeolidiella species can be double at the distal end of the row, the cerata arise from the same lateral duct. This is not so in Aeolidia , the subsidiary distal rows (and there are more than two of these) arise from separate branches of the lateral duct. In addition, the radular tooth of Aeolidiella is deeply emarginate and has a cusp (in some species it can be widely emarginate and the denticles within the gap smaller than those on the lobes), there is a pair of large oral glands, and the renal pore lies just below and in front of the anus. Though the type species has, like Aeolidia papillosa , simple rhinophores, some of the other Aeolidiella species have swellings or distinct lamellae. Aeolidiella is not quite so easily separated from Spurilla and Berghia . This separation has been a problem for a long timeÐThiele’s (1931) solution was to relegate Aeolidiella (as Eolidina ), Spurilla and Berghia to subgeneric status. Presently, they are considered to be genera. I distinguish Aeolidiella from Spurilla and Berghia by the long forwardly curved rows of cerata and the positions of the anus and renal pore.