158 BRITISH AVONIAN CONODONT FAUNAS 
Neoprioniodus barbatus (Branson & Mehl) 
Plate 21, figs. 4-7 
1934 Prioniodus barbatus Branson & Mehl : 288, Pl. 23, figs. 19, 20. 
1934 Prioniodus cornigey E. R. Branson : 329, Pl. 28, fig. 2. 
1938 Prioniodus barbatus Branson & Mehl; Branson & Mehl: 144, Pl. 33, fig. 21, pl. 34, 
figs. 28, 32. 
1938 Prioniodus cornigey (?) E. R. Branson ; Branson & Mehl : 143, Pl. 34, fig. 19. 
1944 Prioniodus barbatus Branson & Mehl; E. B. Branson : 221, Pl. 39, figs. 28, 32. 
1944 Prioniodus corniger (?) E. R. Branson ; E. B. Branson ; 221, Pl. 39, fig. 19. 
1949 Prioniodus barbatus Branson & Mehl ; Thomas : 411, Pl. 4, fig. 26. 
1949 Prioniodus cornigey E. R. Branson ; Thomas: 411, Pl. 4, fig. 27. 
1956 Prioniodina barbata (Branson & Mehl) Bischoff & Ziegler : 160, Pl. 13, figs. 19, 20. 
MATERIAL. 674 specimens : figured, X 259, X 260, X 261, X 262. 
RANGE. North Crop KL 13-ZL 9, Avon Gorge K 21-C 16. 
DescripTION. The anterior denticle is very tall, slender, laterally compressed, and 
ovate in cross-section. It is continuously and gently recurved toward the posterior, 
terminating in a fine point. The posterior bar is fairly deep, being deepest at the 
anterior and shallowing regularly towards the posterior. It bears 9 to 12 tall needle- 
like denticles, sub-circular in cross-section, which are fused at their bases but free at 
their tips. In the posterior part there is some twisting of the bar and it is down- 
curved slightly. 
The basal cavity is situated on the aboro-posterior side of the anterior denticle, 
which is produced below the posterior bar to form an aboral process. The complete 
aboro-posterior surface is excavated, though there is comparatively little flaring of 
the lips, and the cavity may run for a short distance beneath the posterior bar. In 
most specimens the aboro-posterior outline of the aboral process is gently convex, 
but in some specimens a flange tends to develop, making it sigmoidal in outline 
(6.62 Plvan; fiero): 
REMARKS. This appears to be a very common Avonian species, especially in the 
middle of the Z Zone. 
Neoprioniodus confluens (Branson & Mehl) 
Plate 21, figs. 2a, b, 8a, b 
1934 Prioniodus confluens Branson & Mehl (partim) : 206, Pl. 15, fig. 6, (non Pl. 15, fig. 7=N. 
alatus). 
1934 Euprioniodina prona Huddle (partim) : 52, Pl. 6, fig. 19, (non Pl. 11, fig. 8= Euprioniodina 
alternata). 
1939 Prioniodus alatus Hinde ; Cooper: 404, Pl. 46, figs. 6, 8. 
1949 Pyrioniodus aphanes (Cooper) Thomas : 411, Pl. 4, figs. 20, 34. 
1949 Prioniodus obtusus Branson & Mehl ; Thomas 408, Pl. 1, figs. 1, 7. 
1955 Prioniodus prona (Huddle) Sannemann (partim) : 152, Pl. 3, fig. 1 only. 
1957. Prioniodina prona (Huddle) Ziegler in Fliigel & Ziegler : 49, Pl. 4, fig. 6. 
1961 Neoprioniodus avmata (Hinde) Scott & Collinson (partim) : 127, Pl. 2, fig. 24, (non 
Pl. 2, fig. 22=N. armata). 
