CEPHALOPODA— ORTHOCHOANITES. 



103 



DiGONIOCERATIDA. 



XLVII. Tripteroceras Hyatt. 

 Compressed orthoceracones or cyrtoceracones, subtriangular in 

 section, with broad, dorsal and ventral lobes and acute lateral 



Fig. 1328. Solenocheilus collectus^ views of two individuals. Fig. 1329. Tripteroceras 

 After Meek and Worth en, 111. Geol., V,) planoconvexum. (After 



Clarke, Pal. Minn.) 



saddles; siphuncle ventral and nummuloidal. Ordovicic-Devonic. 

 129. T. planoconvexum (Hall). (Fig. 1329.) Ordovicic. 



Fig 1330. Tripteroceras oweniy three views of specimen. Fig. 1331. Tripteroceras 



After Clarke, Pal, Minn. ) planidorsaiu?n, fragment. 



(After Clarke, Pal. Minn.) 



