Kaszab Zoltán (szerk.): A Magyar Természettudományi Múzeum évkönyve 74. (Budapest 1982)

Szabó, J.: Lower and Middle Jurassic Gastropods from the Bakony Mountains (Hungary). Part IV.: Neritacea, Craspedostomatacea, Amberleyacea (Archaeogastropoda)

ANNALES HISTORICO-NATURALES MUSEI NATIONALIS HUNGARICI Tomus 74. Budapest, 1982 p. 17-33. Lower and Middle Jurassic Gastropods from the Bakony Mountains (Hungary) Part IV: Neritacea, Craspedostomatacea, Amberleyacea (Archaeogastropoda) by J. SZABÓ, Budapest Abstract — Four of the here described eighteen species and one of the genera are new: Neritopsis (Neritopsis ) papodensis sp. n., Neritopsis (Neritopsis ) spiniger a sp. n., Chartronella noszkyi sp. n. and Boeckhia boeckhi gen. & sp. n. (Paraturbinidae). With 1 figure and 3 photoplates. Systematic descriptions Family Neritopsidae GRAY, 1847 Genus NERITOPSIS GRATELOUP, 1832 Neritopsis (Neritopsis) elegantissima HÖRNES, 1853 Plate I: figs. 1-3. 1853: Neritopsis elegantissima HÖRNES, p. 763. 1861: Neritopsis elegantissima HÖRN.- STOLICZKA, p. 179, pl. III. fig. 7. Measurements: H HL HA W D A Plate I: figs. 1-3 10 9 7.5 6.5 10 112° Material : Four, definitely juvenile specimens in good state of preservation. Shape : Shell dextral, low-spired, subglobose with a broad elliptical aperture. Peristome extends like a trumpet, bearing an angulation at the suture, only. Parallel with the narrowly callous inner lip, a shallow furrow runs, resulting a pseudoumbilicus. Ornament : Excepting the embryonal part, shell is covered by spiral cords of two kinds alternating each other. Strong varices and growth-lines are crossing the spiral elements collabrally. In the beginning, varices are rounded, but becoming sharper and higher on the subsequent shell regions. Generally, they run from suture to suture, or to the basal furrow. Embryonal shape and ornament: One of the specimens shows a fragment of its larval shell. Nucleus is lacking, but obviously the protoconch consisting of about one and a half whorls. Its shape is similar to the adult's but without any ornament. The end of the embryonal shell is marked by the onset of the adult sculpture. Distribution : Northern Alps: Hierlatz Limestone; Bakony Mts., Sümeg: ? Upper Sinemurian. Remarks : STOLICZKA'S figure shows two kinds of varices alternating each other. This cannot be observed on the specimens from the Bakony Mts. but the strength is variable comparing the specimens. Owing to the fewer number of varices and the orbicular peristome Neritopsis taramellii GEMM. G. G., 1879 and Neritopsisjjraeclara SEG., 1895 (GEMM. M., 1911) are distinguishable. However, the figures show different views, and due to this fact, the separation the mentioned species needs further study. Annls hist.-nat. Mus. natn. hung., 74, 1982 2 Természettudományi Múzeum Évkönyve 1982