92 BRITISH AVONIAN CONODONT FAUNAS 
which tend to decrease in size anteriorly. Three very small, confluent, laterally 
compressed denticles are developed on the posterior edge of the apical denticle. 
These are of minute size. The anterior aboral lateral face of the apical denticle is 
very strongly expanded laterally. whereas that of the outer lateral face is flat to 
feebly convex. The posterior bar is shallow and strongly laterally compressed, its 
outer lateral face being flat and its inner very feebly convex. The apical denticle is 
incurved as well as recurved. 
Euprioniodina sp. 
Plate 22, figs. 15a, b 
MATERIAL. 16 specimens : figured, X 85. 
RANGE. Avon Gorge K 4-Ke I. 
DEscRIPTION. The apical denticle is relatively short and compressed, with a 
denticulate anticusp equal in length to the apical denticle. The apical denticle is 
strongly compressed laterally, with sharp anterior and posterior edges. The anticusp 
is a continuation of the main denticle and both are slightly concave inward. The 
anticusp bears up to 5 laterally compressed denticles, the anterior margins of which 
are subparallel to the apical denticle. The posterior limb is long and thin, and is 
sharply bowed immediately posterior to the apical denticle, with little additional 
bowing behind this. The entire unit is sharply arched. The posterior limb is 
straight and bears at least 14 confluent, sub-equal, sub-rounded to laterally com- 
pressed denticles. The minute pit is located at the base of the cusp and has slightly 
flared lateral lips. The pit is deep, with a sharp point extending into the base of the 
apical denticle. 
Genus GENICULATUS Hass 1953 
1953 Geniculatus Hass : 77. 
TYPE SPECIES. Polygnathus ? claviger Roundy 1926. 
Geniculatus sp. 
Plate 31, fig. 24 
MATERIAL. 2 Specimens : figured X 327. 
RANGE. Scotland DUN 59. 
DESCRIPTION. Two broken specimens are present in one sample from Dunbar. 
Both specimens are anterior bars which are greatly inflated and bear a series of 
laterally compressed fused denticles with free chevron tips. In aboral view the bar 
is broad and has a fine median groove. 
RemMARKsS. The inflated bar enables the present specimens, although broken, to 
be referred to Geniculatus. 
