INVERTEBRATE PALAEONTOLOGY. 



227 



Genus LIOPISTHA, Meek. 



Synon.—Cardium (sp.), Roemer (1849), Texas, 405; aud (1852) Kreid. von Texas, 48 (not Linn.). 



Plioladomya (sp.). Meek and llayden (1856), Proceed. Acad. Nat. Sci. Philad., VIII, 81.— iStoliczka 



(sp.), (1870), Palawnt. Indica, III, 79, pi. II, figs. 10-11 (not Sowerby). 

 Liopistha, Meek i 1864), Smithsonian Check-List N. Am. Cret. Fossils, 12 ami 32 (as subgenus).— 



Conrad (1873), Snppl. Kerr's Geol. Report N. Car. (issued in advance of (lie report). 



28 (as a genus). 

 Cymclla, Meek (18C4), Smithsonian Check-List N. Am. Cret. Fossils, 12 and 32 (as a. subgenus). — 



Conrad (1873), Kerr's N. Car. Geol. Report (suppl.), 10 (as a genus). 

 Poromya (sp.), Stoliczka, (1870); Pakeont. Indica, III, 38 (not Poromya, Forbes, 1844). 



Etyin. — Atwr, smooth : hmaQe, behind. 

 Type. — Cardium elegantulum, Roemer. 



Illustrations of typical Liopistha. 



Fig. 20. 



Fijr. 2.;. 



Fig. 24. 



Fig. 21. 



Fig. 22. 



Liopistha protexta, Conrad. 



Fig. 20. Exterior of right valve, natural size. 



Fig. 21. Hinge of same, magnified two diameters, te give a general idea of its appearance. 



Fig. 22. The same of left valve, with only the anterior conical tooth preserved. 



Fig. 123. Dorsal view of right valve, magnified, to show the projection of the hinge-teeth. 



Fig. 24. Hinge and adjacent parts of same more highly magnified, and turned so as to be seen more from 

 the inner side, to show details of teeth and pits ; a. t. being the anterior tooth ; a. p., the ante- 

 rior pit ; p. t., the posterior tooth ; p.p., the posterior pit ; and/., the fulcrum. 



