Kaszab Zoltán (szerk.): A Magyar Természettudományi Múzeum évkönyve 73. (Budapest 1981)

Vörös, A.: A survey of the Rhaetian (Upper Triassic) Bivalvia from Borzavár (Bakony Mts., Hungary)

Genus HOMOMYA AGASSIZ, 1843 Homomya cf. lariana (STOPPANI, 1857) (Plate II: 13) *1857: [Pholadomya] Lariana STOPPANT, Studii geol. p. 370.: 1861 : Pholadomya lariana STOPP.

—STOPPANI, Couches à Avicula.

.., p. 44, pi. 3, fig. 4-6. 1962: Homomya lariana (STOPPANI) 1857. — ALASSINAZ, Retico Endine, p. 354, pl. XXVIII, fig. 2. vl964: Homomya lariana (STOPPANI), 1861 — VÉGH, Rhät. Südl. Bakonygeb., p. 44, 82, pl. III fig. 28-29. Material : two incomplete internal casts. — Locality : Borzavár, Rhaetian yellow limestone. Description : The specimen is of small size (length: about 4 cm) for the genus; moderately inflated. The outline is elongate subelliptical; inequilateral. The anterior and the ventral margins form a continuous curve; the posterior margin is more strongly arched. The dorsal margin can not be well seen but it appears to be nearly straight. The umbo is broken but it must have been relatively flat and low. The internal cast shows traces of concentric growth rugae: about 7 in a centimetre interval. Some of them show irregular bifurcation toward the posterior end. Remarks: A characteristic feature of H. lariana, the slight radial sulcus near to the anterior margin, can not be observed on the specimens from Borza vár because of their incomplete preservation. From the point of view of ornamentation, this species stands close to H. lagenalis (SCHAFHÄUTL, 1852) and H. caffii DESIO, 1929, the latter however has more elongate, upcurved outline and more massive umbo, while H. lagenalis shows an obliquely elongate outline, with strongly expanded posteroventral part. Distribution : Rhaetian of the Southern Alps and the Bakony Mts. (Hungary). Homomya cf. caffii DESTO, 1929 (Plate II : 14) 71861 : Pholadomya lagenalis SCHAFH.

—Stoppani, Couches à Avicula.

. ., (pars), p. 43, pi. 3, fig. 3 (non fig. 1-2.) *1929: Homomya Caffii DESIO, Albenza, p. Ill, pl. I, fig. 22a-b. Material : An incomplete internal cast. — Locality : Borzavár, Rhaetian yellow limestone. Description: The specimen is of medium size (length: more than 5 cm) for the genus; strongly inflated. The outline is elongate, subelliptical, very inequilateral. The anterior, ventral and posterior margins are broken but seem to be evenly arched. The dorsal margin is concave upwards. The whole posterior part seems to be upcurved. The umbo is massive, prominent. The internal cast shows the traces of concentric growth rugae: about 5 in a centimeter interval. Remarks : One of the specimens figured by STOPPANI (I.e.) under the name P. lagenalis was regarded by DESIO (I.e.) as a representative of his H. caffii. This species has an ornamentation similar to H. lariana (STOPPANI) but differs from the latter by its more elongate and upcurved posterior part and by its more massive umbo. H. rotaensis DESIO, 1929 is closely allied to H. caffii but, according to the above author, it has less elongate outline, less prominent umbo and less regular growth rugae. Distribution : Rhaetian of the Southern Alps and the Bakony Mts. (Hungary).