(Uljanin, 1884)
Description
— Gonozooid rather small, 3-9 mm with thin and delicate test. Intestine dextrally coiled, anus median. The testis is in an oblique line forward and upward, reaching to almost M2 (however, there is large variation in the position of the frontal end, it may reach only M5 but can extend also to M1). The developing testis extends forward in the body cavity, growing gradually to the left and pressing between M3 and the body wall, eventually outside M2 also. Ovary ventro-lateral near M7. Gills in numerous pairs, attached anteriorly and dorsally behind M3, extending rearwards, curving just before M6 and turning forwards to the attachment point at M5. Endostyle long, from between M2 and M3 to almost M5. Dorsal nerve ganglion just behind M3. Anterior aperture with a twelve lobed fringe, posterior aperture with an eight lobed fringe.
The variety Dolioletta gegebauri var. tritonis Herdman, 1888 is larger and more oceanic than the form described here above (Dolioletta gegenbauri s.s.). It can be up to 17 mm in length and the gill slits extend further forward and are attached just in front of M5.
Size
Length of test 3-9 mm, even 15 mm
Depth range
Distribution in the North Sea
Northern North Sea
World distribution
Northern, Central and subtropical S Atlantic Ocean; tropical and temperate SW Indian Ocean, tropical W and SW Pacific Ocean; also in the Mediterranean Sea.