ART. 12 CLASSIFICATION OF CONODONTS ULRICH AND BASSLER 53 



PANDERODELLA SUBCRASSA. new species 



Plate 9, fig. 14 



Similar to P. truncata luit much larger and with relatively much 

 coarser denticles, shorter form, thicker flange, and somewhat curved 

 crest. The denticles decrease in size from the broader end. 



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

 Tenn. 



H olotyjye.— C?it. No. 11042, U.S.N.M. 



PANDERODELLA MAXILLARIS, new species 



Plate 9, fig. 21 



Characterized by the great thickening of the anterior part of the 

 jawlike plate and the swelling just under the denticles. The flange 

 is only of moderate Avidth. 



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

 Tenn. 



Cotypes.—Csit. No. 11041, U.S.N.M. 



POLYGNATHELLUS, new genus 



Similar to Panderodella with a curved crest made up of joined, 

 mostly sharp-edged denticles, longest in the middle and shortening 

 towards the two ends. On the convex side there is a very narrow, 

 smooth basal expansion, while on the concave side occurs a wider 

 flange, the upper surface of which is tuberculated as in Polygnathus. 

 In side view the plate, especially the crest, reminds of Bryantodus, 

 hut the development of the concave tuberculated basal expansion 

 on one side is quite different and causes us to believe the generic re- 

 lations are more with Polygnathus. 



Genotype. — Poly gnathellus typicalis., new species. 



Range. — Upper Devonian, Early Mississippian. 



Besides the two species herein described, Prioniodus colligatus 

 Bryant, 1921, appears to have the characters of this genus, 



POLYGNATHELLUS TYPICALIS, new specr-is 



Plate 1, figs. 1-3 



Our views illustrating the two sides and the bottom of the plate 

 bring out the features discussed above in the generic diagnosis as 

 based upon this the tjq^e species. 



Occurrence. — Devonian (Rhinestreet) : Shaleton, N, Y. 



Cotypes.—Qvit. No. 11304, U.S.N.M. 



