486 



THE PALEONTOLOGY OF MINNESOTA. 



H'Uissitu'iil ion of palrozok 1 Lui 



Family CYPRICARDINIID^E, (Provisional.) 

 GENUS: Uypncardinia, Hall. 



Family CYRTODONTID^E, Ulrich. 



GENERA : ? Cypricanlites, Conrad; Cgrtodonta, Billings; liuiii/i-oiliinln, Ulrich; Mntlicrin, Hillings; Ortonclla, 

 Ulrich. ? Ptycliodesnut, Hall; \'annxcmM, Hillings; Whitella, Ulrich. 



Suborder HOMOMYARIA. 



Mantle lobes either separate or united posteriorly. The two adductor muscles of nearly equal 

 strength. 



Family ARCID^E, Lamarck. 

 GENERA- Carbonarca, Meek and Worthen; Macrodon, Lycett; Nyassa, Hall; ? Spenotus, Hall. 



Family PARARCID^E, (Provisional). 



GENEUA : Cardiola, Broderip; Cardiopsis, Meek and Worthen; Dexiobia, Winchell; Olyptocardia, Hall; 

 Lunulicardium, Mi'mstcr; Oroecardium, Herrick; Panenka, Barrande; Paracardium, Hall; 

 Pararca, Hall. 



Family NUCULUXE, Gray. 



GENERA : ? Clidophonis, Hall; Ctenodonta, Salter (Tellinornya, Hall ); Goniodon, Herrick; Nucula, Lam- 

 arck; Nuculanu, Link; Nuculites, Conrad; Palceoneilo, Hall; ? Pyrenommis, Hall; Yoldia, 

 Moller. 



Family LYRODESMID^E, Ulrich. } 

 GENERA: Allodesma, Ulrich; Ischyrina, Billings; Lyrodesma, Conrad; Technoptyorus, Miller. 



Family TRIGONID^E, Lamarck. 

 GENERA : 'i Cytherodon, Hall; ? Schizodus, King. 



Family UNIONID^E 

 GENERA : ? Amnigenia, Hall; ? Anthracosia, King; Prisconaia, Conrad. 



Family ELYMELLIDyE, (Provisional). 

 GENERA : Elymella, Hall; Glostites, Hall. 



Order SIFIIONIDA, Woodward. 



Mantle lobes more or less united; siphons of varying lengths, either separate or united, arc 

 developed; both adductor muscles well developed. 



* 



Family SOLENOMYID^C, Gray. 



GENKHA : Soltnomna, Lamarck; Clinopistha, Meek and Worthen; Phtlmnia, Hall. 



Family SANGUINOLITID^, Miller. 



GENERA: Promacrns, Meek: Sanymnoliles, McCoy. 



, , ^.. _t- 



