Description. External morphology. Living animals approximately 11 - 17 mm in length. Body oval, with two marginal bands of similar widths on the mantle edge. Gill and rhinophores are translucent red with a mix of red and white edges. Four to eight unipinnate gill branches. Ten or eleven lamellae on rhinophores. The color patterns of this species can be divided into two distinct morphotypes. Morphotype A (Fig. 3 e) has an opaque white body. The outermost portion of the mantle edge is surrounded by a red margin and a yellow submarginal band with both bands of similar widths. Morphotype B (Fig. 3 f) has a translucent creamy white body with small orange spots on the notum. The outermost portion of the mantle edge is surrounded by a very thin opaque white band, followed by a red and a yellow submarginal band. Buccal mass and radula (morphotype A). The muscular portion of the buccal mass is approximately the same size as the oral tube length (Fig. 6 c). The chitinous labial cuticle found at the anterior end of the muscular portion of the buccal mass bearing bifurcated and short jaw rodlets (Fig. 11 a, b). The radular formula of CASIZ 203059 is 37 x 28.1.28 (Fig. 11 c). The rachidian tooth is flame-like in shape and short. The inner and outer surfaces of the inner lateral teeth have three denticles on each side (Fig. 11 d). The central cusp on the inner lateral tooth is ~ 2 x the length of the adjacent denticles. The middle lateral teeth have a short central cusp with approximately four or five denticles (Fig. 11 e). The outer lateral teeth have a rounded tooth shaped with ~ 2 - 4 denticles (Fig. 11 f). Reproductive system (Fig. 6 d). The thick, tubular ampulla narrows into a diverging short oviduct and long vas deferens. The proximal prostatic portion of the vas deferens is wide and convoluted and transitions into the muscular ejaculatory portion. The long, narrow, convoluted ejaculatory portion transitions into a wider, long penial bulb, which joins with the distal end of the vagina. The thick muscular vagina is elongated and transitions into a larger, spherical bursa copulatrix. At this junction of the vagina and bursa copulatrix, the smaller pyriform receptaculum seminis also connects. The moderately long uterine duct that emerges from the junction of the vagina, bursa copulatrix, and receptaculum seminis enters into the female gland mass. This uterine duct junction also extends proximally on one side and includes a larger portion of the vagina. The female gland mass has small albumen and membrane glands and a large mucous gland.
