Three spp of Crassimarginatella: C. maderensis (Waters, 1898), C. crassimarginata (Hincks, 1880) and C. solidula (Hincks, 1860), occur in the Western Mediterranean. The finding of vicarious avicularia in this last sp justifies its exclusion from the gen Alderina and its new generic attribution. The different stages of autozooidal development are followed out in these 3 spp. Ooecia formation reveals a prominent entozooidal structure, instead of an hyperstomial one, as traditionally described. The communication organs present uniporous pore plates. They seem to belong to a particular type of dietella, very primitive and simple in C. maderensis, while in C. solidula, the heavier calcification brings about a closer porechamber-like structure. Comparative measurements of specimens from Mediterranean and from other geographical areas are given. Ecological needs and distribution of the spp are discussed. |
