ART. 12 CLASSIFICATION OF CONODONTS ULRICH AND BASSLER 21 



PRIONIODELLA CONFERTA, new species 

 Plate 10, fig. 25 



Especially distinguished from other species of this genus by its 

 strong, closely approximated denticles set obliquely to the bar. The 

 lower half of the denticles is concave and seems to be set into a 

 transversely striated, outwardly concave sheath, therein suggesting 

 the confluent denticles characterizing Bryantodus. However, none 

 of the denticles can be distinguished as the main cusp which is 

 always strongly indicated in Bryantodus. 



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

 Tenn. 



Holotijpe.—Qsit. No. 10989, U.S.N.M. 



BRYANTODUS, nev/ genus 



Like Prioniodina, but denticles with sharp, laterally confluent 

 edges. The main cusp is proportionately much larger and as a rule 

 more conspicuous in its width and broadly expanded sides confluent 

 with the adjacent denticles. The base forms a narrow flange-like 

 expansion on both sides, with a characteristic downward projection 

 on the inner side beneath the main cusj), serving perhaps for secur- 

 ing attachment in the jaw of the animal. The denticles are con- 

 nected by a membrane-like extension of their edges, a feature much 

 better developed in this genus than in the otherwise related genus 

 Pnoniodin^. 



Genotype. — Bryantodus typicas., new species. 



This new generic name is in recognition of the studies upon fossil 

 fishes by W. L. Bryant, director of the Park Museum, Providence, 

 R. I . 



Range. — Upper Devonian and Early Mississippian. 



Of previously described species, Pr'iordodus cristatus, P. raacro- 

 dentatus^ P. ohtusus, P. parvulus., P. parvus., P. retusus, and P. 

 spatulatus Bryant, 1921, Polygnathus duhius Smith, 1907, Polyg- 

 nathus duplicatus P. imniersus and P. radiatus Hinde, 1879, and 

 Prioniodus poUtus Hinde, 1879, belong to Bryantodus. 



BRYANTODUS TYPICUS, nev/ species 



Plate 0, figs. 11, 12 



Bar slightly curved, with an accentuated downward turn at the 

 anterior extremity, surmounted by 10 relatively short, flat, confluent 

 denticles setting well back from the flange-like expansion of the bar. 

 Main cusp strong, nearly three times as wide at the base as any 

 other denticle, slightly recurved toward its top, with thin, sharp 

 edges, the latter appearing on the inner side of tooth like a mem- 



