A new species of the dorid nudibranch genus Geitodoris Bergh, 1892 (Gastropoda, Opisthobranchia) from New Zealand

Geitodoris sticta new species is described and illustrated. This is the first time that a Geitodoris species has been recorded for New Zealand waters. The history of the use and classification of the genus Geitodoris Bergh, 1892 is reviewed, specially emphasising its separation from the obviously closely related Discodoris Bergh, 1877. Geitodoris is maintained on the presence of a definite set of spatulate marginal radular teeth, contrary to Discodoris which is characterised by a gradual change in the size and shape of the teeth, the outer ones being hook-, blade- or needle-like. In terms of Ortea and Ballesteros' (1981) subgeneric arrangement of ten of the sixteen presently recognised Geitodoris spp., clearly the new species would stand alongside G. bonosi Ortea & Ballesteros, 1981 in their subgenus Verrillia. The new species is distinguished from G. bonosi in having ill-defined patches of brown pigment on the mantle (not definite spots) and marginal teeth of one kind, spatulate (no needle-like outer ones), and lacking a vestibular (?penial) gland. A comparison is made with twelve other species, eight recognised Geitodoris spp. (two mentioned but not assigned to a subgenus and six not considered by Ortea and Ballesteros, two of these species having been described after their review), and four Discodoris spp. with a Geitodoris-like radula. The new species is separable from all of them. It is closest to G. bacalladoi Ortea, 1990, differing in having indefinite patches of brown pigment, flattened tubercles of two sizes, tripinnate gills, trapezium-shaped jaws with rod-like elements and asymmetrical marginal teeth (side view). In two cases the distinction is not absolutely certain because the descriptions are inadequate.