174 BRITISH AVONIAN CONODONT FAUNAS 
REMARKS. Ozarkodina macer (Branson & Mehl) as here defined, includes a group 
of ozarkodinids which are characterized by having asymmetrical anterior and 
posterior limbs. The outline of the denticles of both the anterior and posterior 
blades is similar in lateral view. O.macer resembles O. cf. congesta in the outline of 
the blades in lateral view, but in O. macer the anterior and posterior limbs are 
asymmetrical whereas in O. cf. congesta they are symmetrical. 
Compared with Ozarkodina macra the blade of Ozarkodina macer is thinner. 
Ozarkodina macra Branson & Mehl 
Plate 27, fies. 12, °20, 21 
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1931 Bryantodus equalis Cooper : 234, Pl. 28, fig. 9. 
1931 Bryantodus subequalis Cooper : 234, Pl. 28, fig. 11. 
1934 Ozarkodina macva Branson & Mehl : 192, Pl. 17, fig. 5. 
1934 Ozarkodina vegularis Branson & Mehl: 287, Pl. 23, figs. 13, 14. 
1938 Ctenognathus firmus Stauffer : 425, Pl. 48, figs. 2, 6, 15. 
1955 Ozarkodina rvegularvis Branson & Mehl ; Sannemann : 133, Pl. 6, figs. 3, 7 only. 
1956 Ozarkodina rhenana Bischoff & Ziegler : 153, Pl. 14, fig. 19. 
1957 Ozarkodina ballai Bischoff & Ziegler : 74-75, Pl. 13, figs. 1, 2. 
1957 Ozarkodina macra Branson & Mehl ; Bischoff & Ziegler : 77, Pl. 12, figs. 13a, b, Pl. 13, 
figs. Ioa, b. 
1957 Ozarkodina cf. macya Branson & Mehl ; Bischoff & Ziegler : 78, Pl. 13, fig. 11, Pl. 19, 
fig. 43. 
MATERIAL. 36 specimens : figured, X 296, X 298, X 297. 
RANGE. Avon Gorge K 2-Z 18, North Crop KL 2-KL 16. 
DESCRIPTION. The aboral edge in lateral view is slightly arched. The anterior 
and posterior blades are of almost equal length. and bear 8-12 straight, posteriorly 
inclined denticles, fused for the greater part of their length but free at their tips. The 
anterior blade is thicker than the posterior blade. The apical denticle is two to three 
times as wide as the denticles of the anterior and posterior blade. It is inclined to the 
posterior at an angle of 70°. The small circular basal cavity is situated immediately 
beneath the apical denticle and the aboral edge is sharp. 
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Ozarkodina parva (Huddle) 
Plate 27, fig. 18 
1934 Bryantodus parvus Huddle : 74, 75, Pl. 4, fig. 9. 
1939 Bryantodus orthus Cooper : 385, Pl. 43, figs. 33, 34. 
1939 Subbryantodus ? scitulus (Branson & Mehl) Cooper : 417, Pl. 43, figs. 35, 36. 
MATERIAL. 107 specimens : figured, X 299. 
RANGE. Avon Gorge K 3-C 7, North Crop KL 2—ZLA 32. 
DEscRIPTION. The blade is short, thin, symmetrical and slightly arched. The 
apical denticle is subcentral, flattened, sharp edged and acutely pointed to the poster- 
ior. The blade denticles are closely appressed and similar to the apical denticle in 
outline, inclination and insertion. They number 7 to 12 on each side of the apical 
