Tyrinna Bergh, 1898

Schrödl, M. & Millen, S. V., 2001, Revision of the nudibranch gastropod genus Tyrinna Bergh, 1898 (Doridoidea: Chromodorididae), Journal of Natural History 35, pp. 1143-1171 : 1145-1146

Tyrinna Bergh, 1898

Generic diagnosis. Body elongate, mantle wide, foot narrow. Notum smooth or bearing small, low bosses. Few, chunky spicules may be present in the mantle tissue. Body whitish with orange to red spots scattered around the notal margin or over the whole notum. Anterior foot margin separated into two lips, the foot corners may be slightly prolonged laterally. Oral tentacles long, digitiform with a blunt tip, with a deep medial longitudinal groove. Five to six bi- to tripinnate gills in a semicircle in front of the anal papilla. Two or three submarginal rows of mantle dermal formations (MDFs), the inner row containing the largest ones. Within a thin, spherical, muscular capsule there are highly vacuolized cells. In larger MDFs the vacuolar cells are clustered in folded layers. Jaw rodlets bi®d or seldom tricuspid. Radula broad with about as many teeth per half row as rows. Rhachidian teeth variable in shape, small and claw-like bearing equal sized denticles, or elongate with pairs of denticles, and with or without a projecting median cusp. First laterals usually with inner and outer denticles, all other laterals only with outer denticles; these may be completely reduced except on the outermost teeth. Salivary glands and caecum present. Vas deferens long, with a relatively short prostatic portion followed by a long muscular portion, without armature. Common genital vestibule; branched vestibular accessory glands may be absent or present. Vagina long, narrow and convoluted. Bursa copulatrix and receptaculum seminis close together, short-stalked, inserted on the vagina.

Type species. Tyrinna nobilis Bergh, 1898 .

Additional species. Tyrinna evelinae ( Marcus, 1958) , T. burnayi ( Ortea, 1988) .