194 BRITISH AVONIAN CONODONT FAUNAS 
Later, Branson & Mehl (1934A) erected the genus Subbryantodus for ‘“‘ arched 
denticulate bars . . . with one or both limbs laterally flexed . .. denticles ... 
laterally compressed . . . closely crowded . . . one denticle of exceptional size, 
the apical denticle at the apex of the arch . . . the aboral edge of the bar excavated 
beneath the arch apex by a long pit that tends to extend as a distinct groove along 
the edge of each limb ”’. 
Branson & Mehl suggested (p. 285) that Subbryantodus differed essentially from 
Prioniodina in the fused, laterally compressed denticles and tendency toward a split 
aboral edge. We consider that these differences are not of generic significance and 
regard Subbryantodus as a junior subjective synonym of Prioniodina Bassler 1925. 
Prioniodina eireica (Collinson & Druce) 
Plate 28, fig. 13 
Subbryantodus eiveica Collinson & Druce (in press). 
MATERIAL. I Specimen : figured, X 315. 
RANGE. North Crop 3D 17. 
DescrieTIon. The distinctive features of this species are the minutely denticu- 
lated and very short depressed anterior bar, the massive, recurved, wide, pointed 
apical denticle, and the short straight feebly denticulated posterior bar. Below the 
Apical denticle 
Blade denticles 
Posterior 
bar 
Anterior bar 
Basal cavity 
Fic. 38. Pvioniodina sp. showing morphological terms used in the text. 
