Cystodytes

Cystodytes sp.

(Figure 26)

Stations. TA 35 (MNHN A3 CYS 139). TA 52 (MNHN A3 CYS 140).

The colonies in life are large white crusts 0.5 to 1cm thick (Fig. 26). The surface layer is smooth, thin and devoid of spicules. The zooids are withdrawn and included in complete capsules of plate-like spicules densely packed in the translucent tunic, giving a white colour to the fixed colonies. Below the capsule layer the tunic contains sparse brown pigment cells. Removed from the tunic the tips of the siphons are light brown but the remaining body wall is clear. The male gonad is a rosette of about 10 lobes and the sperm duct is straight. The ovary and testes are not mature in a same zooid but both sexes can be found in a same colony. The ovary includes a large protruding oocyte and several smaller ones. No fully developed tadpoles have been found but several regressed ones are present in the deepest part of the colonies; they are transparent bodies in which the otolith and ocellus remain but not any other organ. They are not included in capsules.