22 



94. Dreissenia siibearinata Iflyt. Dealt. 



D. testa solida, subtrigona, convexa, carinata, striis rugisque concentricis instructa; 

 margine dorsali recto, 2 /s tolius longitudinis conchae aequante; margine postico arcuato, 

 basi antice sinuata, in medio, in ea scilicet parte, qua byssus emittitur, excavata; umbonibns 

 acutis, paullo incurvis; septo crasso, transversim striato cum lamina parvula agnata. 

 Long, speciminis, quod exstat, 20 lin. Long., alt., lat. ratio 100, 64, 50. 

 Mytilus subcarinatus Desh. Crim. pag. 62. Tab. 4. fig. 12. 13. - Dreissena sub- 

 carinata Nyst Coq. tert. Belg. pag. 264, - - Bronn Ind. pal. p. 439. 



Species, forma sua Mytilo Balatonico similis, in stratis formationis terliariae ad Kertsch 

 Russiae occurrit. 



95. Dreigsenia Balaton lea .Tlyt. Goldf. 



D. testa magna, crassa, trigona, concentrice rugoso-striata, utrinque carinata, dorso 

 alto arcuato, subangulato, paene compresso; basi antice sinuata; area basali lunulaque cor- 

 data; fissura byssi magna et late hiante; umbonibus magnis arcuatis; lamina septo crasso, 

 trigono, transverse striato affixa. 



Mytilus palatonicus Goldf. Petref. Germ. II. pag. 172. Tab. CXXX. fig. 2. a. b. c. - 

 Congeria palatonica Partsch Ann. d. Wien. Mus. I. pag. 100. Tab. 12. fig. 9 12. 

 Dreissena palatonica Nyst Coq. tert. Belg. pag. 163. ?Enocephalus mytiloides Mttnst. 

 in Keferst. Zeitg. 1831. IX. 92. (ex auctoritate clar. Bronn.) 

 In stratis tertiariis ad Viennam nee non ad litora lacus Balaton Hungariae occurrit. 



96. Dreissenia triangnlaris Congeria Partscli. 



D. testa triangulari, convexa, carinata, concentrice striata; umbonibus inclinatis, incur- 

 vis, magnis; septo parvulo. 



Congeria triangularis Partsch Ann. d. Wien. Mus. I. pag. 99. Tab. 12. fig. 5 8. 

 ex parte. Dreissena triangularis Nyst Coq. Belg. pag. 264. Bronn Ind. pal. pag. 

 439. Naumann Geogn. Tab. LXVIII. fig. 5. 



Forma singularis, lata, triangulo, cujus latera duo aequalia sunt, baud disshnilis. 

 E formatione Viennensi tertiaria. 



9*. Dreissenia Partscliii Congeria Czjzeli. 



,,D. testa ovali, apicibus simpliciter arcuatis, valvulis crassis, convexis, concentrice 

 striatis, baud schistosis, sine appendice tumescente semilunari." 

 Long. spec, adult, fere 24 lin. efficit; saepius minora occurrunt. 



Congeria Partschii Czjzek in naturw. Abh. herausg. v. W. Haidinger. vol. III. pag. 129. 

 Tab. XV. Myt. subglobosus Goldf. Petr. II. pag. 173. Tab. CXXX. fig. 3. a. b. c. 



