ALBERT

Description: The examination of two aberrant Pteropods collected during a trip with the whale factory-ship \xe2\x80\x9dm.s. Willem Barendsz\xe2\x80\x9d led to the conclusion that they were animals in a resting stage. The histology and the anatomy of the totally aberrant soft parts was discussed. The shells of the specimens indicate that these animals are the species Clio antarctica Dall, 1908. One aberrant specimen belonging to the species Clio sulcata (Pfeffer, 1879), collected during the same trip with the whale factory-ship, was examined and it shows that this animal was in a stage between the resting stage and the normal, active, stage. Three specimens of the species Clio pyramidata (Linnaeus, 1767, forma lanceolata (Lesueur, 1813), collected by the Texas and the Dana expedition, were studied as they showed the same aberrations from the normal full grown form as the other three animals previously mentioned. It was clear that the three specimens of the form lanceolata were also in a resting stage and their anatomy and histology were identical with those of the aberrant animals of the species Clio antarctica Dall, 1908.\nThe resting stage seems to have developed from a more specialized stage, as a great store of reserve food was present, while the intestinal duct was not functional and, moreover, the gonad was active.\nThe relation and the distribution of the species Clio pyramidata Linnaeus, 1767, Clio sulcata (Pfeffer, 1879), Clio antarctica Dall, 1908 and Clio martensii (Pfeffer, 1880) was studied and it seems better to consider these species as belonging to one polytypic species and, therefore, as synonymous with Clio pyramidata Linnaeus, 1767. It may be very well possible that Proclio subteres Hubendick, 1951 also belongs to the species Clio pyramidata Linnaeus, 1767. And if that is the case, Proclio subteres Hubendick, 1951 is in all probability synonymous with Clio pyramidata Linnaeus, 1767 forma antarctica (Dall, 1908).