Mme PRUVOT-FOL, 1933, p. 400, established the subgenus Tullia for Aplysia juliana QUOY et GAIMARD, and 1934, p. 41 added other species of Aplysia with a distinct sucking disk at the end of the foot. Living animals have been figured and their variation has been described by BABA 1937a, p. 211, and 1949, p. 24 and 125 as Tethys and Aplysia sibogae. In a recent paper, PILSBRY, 1951, beautifully figured and described the living animals as Aplysia (subgen. nov. Metaplysia) badistes nov. spec. He points to the fact (verified in our preserved animals) that the anterior part of the foot-sole also tends to form a sucking disk. However, it is not separated by a (more or less distinct) groove from the rest of the foot (see PILSBRY’S fig. 4) as is the posterior disk. In 1955 a paper was published by MACNAE, who considers that at least five species of the subgenus Tullia belong to one species, ENGEL having suggested this identity when he had the pleasure of seeing Dr. MACNAE in Amsterdam and discussing his old notes on Tullia with him. We agree with him that most specimens of the subgenus Tullia belong to one species, viz. juliana (syn.? sorex). We only accept some Tullia’s (cf. p. 22) as separate species. MACNAE gives valuable remarks on the living animals, their ”progression in the way of a looper caterpillar” and the appearance of the sole of the foot. He observed that the sucking disk is visible only when the animal is ”looping”, and sometimes (not always !) after preservation. Is is probable that the posterior disk is distinct only in specimens which were preserved while the posterior pedal glands were in a state of active secretion. ¹)