AKT. 12 CLASSIFICATION OF CONODONTS ULRICIi AND BASSLER 49 



ANCYRODELLA SYMMETRICA, new species 



Plate S, fi^-. 1 



Evidently a lineal descendant of .1. {Polygnathus) tuberculata 

 Hinde from the Genundewa limestone of western New York. 

 These species differ, however, conspicuously in that A. symvietrica- 

 lacks entirely the coarse tubercules. Among other differences, the 

 flukelike extensions are not definitell}^ separated from tlie anterior 

 part. Again the anterior part of the plate has developed a pair of 

 posteriorily diverging low ridges. 



Occiinxnce. — Mississippian (Hardin sandstone) : Mount Pleasant, 

 Tenn. 



Holoti/pe.— Cat. No. 11008, U.S.N.M. 



ANCYRODELLA MALLEUS, new species 



Plate 7, figs. 1, 2 



Differs from A. symmetrica in the unsymmetrical hammerlike 

 shape which is produced by the reduction or truncation of the an- 

 terior part of plate but resembling it in its bifurcated recurved crest 

 and lack of surface tubercles. 



Occurrence. — Mississippian (Hardin sandstone) : Mount Pleasant, 

 Tenn. 



C oty pes.— C?it. No. 11006, U.S.N.M. 



PALMATOLEPIS, new genus 



Plate more or less irregularly palmate, the crest curved and bi- 

 furcating in its upper half so as to extend a division into each of 

 the two main lobes and its lower end not extending beyond the 

 narrowing lateral areas. Upper surface highly ornamented, usuall}?- 

 with radially or otherwise arranged rows of minute tubercles. Under 

 surface with concentric growth lines and low ridges corresponding 

 to the bifurcated crest of the upper surface. 



Genotype. — Palmatolepis perlohata., new species. 



Range. — Upper Devonian and Lower Mississippian. 



PALMATOLEPIS PERLOBATA. new species 

 Plate 7, figs. 19-23 



Five specimens are figured, two lower (19, 21) and two upper 

 (20. 22) showing the tendency to obsolescence of the lateral branch 

 of the median crest, the irregular although decidedly lobate outline 

 and the decided curvature of the crest. Figure 23 represents a more 

 triangular possible variant of this species. 



