BRITISH AVONIAN CONODONT FAUNAS 75 
Apatognathus varians Branson & Mehl 
Plate 20, figs. 5a, b 
1934 <Apatognathus varians Branson & Mehl: 201, Pl. 17, figs. 1-3. 
non 1939 Apatognathus ? varians Branson & Mehl ; Cooper : 385, Pl. 47, fig. 30. 
1944 Apatognathus varians Branson & Mehl ; Branson & Mehl im Shimer & Shrock : 402, 
Pl. 93, figs. 59-61. 
1956 Apatognathus varians Branson & Mehl ; Bischoff & Ziegler: 145, Pl. 14, fig. 3. 
1958 Apatognathus varians Branson & Mehl ; Klapper: 1085, Pl. 141, figs. 6, 8. 
1961 Apatognathus varians Branson & Mehl; Ethington, Furnish & Wingert : 763, 
Pl. go, fig. 11. 
1961 Apatognathus varians Branson & Mehl; Freyer: 36, Pl. 1, fig. 13. 
1965 Apatognathus varians Branson & Mehl ; Spasov : 84, Pl. 1, fig. 3. 
1965 Apatognathus varians Branson & Mehl ; Ethington : 575. 
MATERIAL. 6 specimens : figured X 42. 
RANGE. North Crop ZLA 9-ZL 9. 
DEscRIPTION. The unit is considerably arched and bowed. The apical denticle 
is laterally compressed, with convex lateral faces, and sharp anterior and posterior 
edges. It is inclined posteriorly and laterally towards the inner side. The anterior 
bar lies in the same plane as the apical denticle, but is twisted inwards distally. It 
bears at least 20 closely crowded, sub-circular, posteriorly-inclined denticles, their 
apices being discrete and pointed. 
The anterior bar is strongly laterally compressed in its distal third, with flattened 
lateral faces, but the inner and outer lateral faces become strongly convex in their 
proximal two-thirds. The posterior bar is short, considerably flexed, about as long 
as that of the anterior and makes an angle of about 20° with the anterior bar. It is 
curved inward, and bears denticles similar to those of the anterior bar, but tending 
to be upright or anteriorly inclined. Both bars decrease in height towards their 
distal extremities. The basal cavity is minute and situated beneath the apical 
denticle. 
On specimen number X 42 (Plate 20, figs. 5a, b) the inner lateral face of the apical 
denticle tends to be flat, but the outer lateral face is strongly convex, the inner lateral 
face of the bars immediately below the apical denticle tending to be rather flattened. 
The two denticles immediately posterior to the apical denticle tend to be larger than 
any of those on the anterior bar. The distal portion of the posterior bar is broken. 
The outer lateral face of the anterior bar is similar in general cross-section to the 
inner lateral face. 
Apatognathus cf. libratus Varker 
Plate 20, figs. 8a, b 
1967 Apatognathus ? librata Varker : 134, 135, Pl. 18, figs. 3, 6, 8, 9, 12, 13. 
MATERIAL. I Specimen : figured, X 58. 
RANGE. Scotland DUN 78. 
DescripTion. The characteristic feature of this species is its virtual bilateral 
