Szekessy Vilmos (szerk.): A Magyar Természettudományi Múzeum évkönyve 53. (Budapest 1961)

M. Nyírő, R.: A new foraminifer species from the Oligocene layers of Törökbálint

Differential diagnosis: Its nearest ally is Amphicoryne tunicata (Hantken). Its author relegated it to the Marginulinae (1875), but it belongs, on the basis of the generic characters, to the genus Amphicoryne. The greatest difference between the two species is that, in Amphicoryne tunicata, also the initial chambers are swollen, they have a Nodosaria character, and the test is ribbed all over. Also, it consists of fewer chambers. Both species occur in the Oligocène. B. microsphaeric form : Morphotypus: One specimen in the Paleontological Department of the Hungarian Natural History Museum; inventory number: M 60/581. Measurements: 0,57 mm long, greatest wicth 0,24 mm. It was found in the clay pit of the brick-works of Törökbálint, from a Bulimina zone. Its age is Rupelian. The microsphaeric form of the Holotype : the test is larger, it consists of 9 chambers, of which the Marginulina-like initial form comprises 7 chambers, with the eighth and ninth being of a swollen, sphaerical shape, and also ribbed. In every other respect, it agrees with the Holotype. Several specimens were found from both the A) and B) types. Some have less bulbous last chambers, or the ribbing is less advanced ; indeed, there are specimens lacking the last, swollen, chamber. Reference : H a n t k e n, M. : Clavulina szabói rétegek (Földt. Int. Évk., 4, Fase. 1, 1875, p. 1-94, Taf. I-XVI).