Matskási István (szerk.): A Magyar Természettudományi Múzeum évkönyve 80. (Budapest 1988)

Pálfy, J.: Middle Triassic rhynchonellids from the Balaton Highland (Transdanubian Central Range, Hungary)

Fig. 3. Drawing of a specimen of Volirhynchia vivida from Felsőörs. The posterior view is to show the well-developed lateral wings. Dimensions: the following table presents the data of the four best preserved specimens from Felsőörs (2-5), while column No. 1 those of the specimen figured by BÖCKH (1873). 1 2 3 4 5 Length 10.0 11.5 9.2 9.5 10.4 Width 10.5 11.1 10.6 9.8 10.2 Thickness 6.0 7.4 6.0 5.1 6.8 Description — External characters : Medium-sized shell, pentagonal in outline. After an early biconvex stage the brachial valve remains strongly convex, while on the pedicle valve develops a pronounced sinus. The maximum width and thickness are situated at 3/4 of the length, at the rounded anterio-lateral corner. The lateral commissure is ventrally arched running through a faint planarea. The anterior commissure is uniplicate, dominated by a high, wide, almost rectangular fold. The posterior part of the shell is smooth, but from about the one third of the length low, blunt costae evolve. Three costae occupy the central fold, while single ones or pairs run ventrally curved on the lateral flanks toward the anterio-lateral corner, forming two very pronounced ventrally projecting Fig. 4. Volirhynchia vivida (BITTNER, 1890): a series of 11 transverse sections through the posterior part of a specimen from Köveskál. Original length 9.5 mm. The crura persisted to 3.0 mm from the posterior end of the shell.