126 BRITISH AVONIAN CONODONT FAUNAS 
1959 Hindeodella deflecta Hibbard ; Helms: PI. 4, fig. 32, Pl. 1, fig. 17. 
1960 Hindeodella germana Holmes ; Zimmermann : PI. 1, fig. 16. 
1960 Hindeodella germana Holmes ; Dvorak & Freyer: PI. 1, fig. 1. 
1961 Hindeodella germana Holmes ; Biidurov : 262, Pl. 3, fig. rr. 
1962 Hindeodella germana Holmes ; Spasov & Stevanovic : 58, Pl. 1, fig. 12. 
1962 Hindeodella sp. Winder : 91, fig. 1, 6. 
1965 Hindeodella germana Holmes ; Spasov : 86, 87, Pl. 1, fig. 10. 
1965 Hindeodella similis Ulrich & Bassler ; Spasov : 87, Pl. 1, fig. 11. 
MATERIAL. 200 specimens : figured, X 180, X 177, X 178, X 179. 
RANGE. North Crop KL 1-ZL 19, Avon Gorge K 3-Z 38. 
DESCRIPTION. The main denticle is fairly massive, laterally compressed, biconvex 
in cross-section, recurved and posteriorly inclined. The anterior lateral process is 
curved inwards at an angle ranging from just a few degrees to nearly go°. The 
considerably laterally compressed anterior lateral process is finely denticulate, often 
with the largest denticles at the anterior. The posterior bar is very thin, compara- 
tively deep, and somewhat arched in some specimens, bearing fine, discrete, pointed 
denticles. The dentition tends to be cyclic, two major denticles being separated by 
three to four minute denticles, all more or less posteriorly inclined. There are up to 
14 major denticles on the posterior bar. The posterior termination is composed of 
flat lying denticles, inclined at a low angle to the horizontal. It may be aborally 
convex (“ upswept ’’) in young forms. 
The basal cavity is small, fairly deep, and situated at the anterior end of the apical 
denticle. 
REMARKS. Throughout the Middle and Upper Devonian, and the Tournaisian and 
Viséan, there occurs a simple hindeodellid with a curved anterior lateral process. 
Many different authors have assigned different names to these hindeodellids, depend- 
ing on minor variations in such features as the amount of deflection. Within our 
collections all types of deflection and various types of dentition can be-seen to inter- 
grade, and it is probable that all these forms belong to the same variable species. 
Further work may show that some of these characteristics may be of specific import- 
ance, but at the present time none can be separated. 
Hindeodella tenuis Clarke 
Plate 28, fig. 27 
1900 Ctenognathus obliquus Hinde (partim) : 344, Pl. ro, fig. 38. 
1928 Hindeodella obliqua Holmes (partim) : 12, Pl. 5, fig. 5. 
1960 Hindeodella tenuis Clarke : 8, 9, Pl. I, figs. ro, 11. 
MATERIAL. 4 Specimens : figured, X 187. 
RANGE. North Crop 3D 12-14/15. 
DESCRIPTION. The present specimens are similar to those described by Clarke. 
The posterior bar is elongated, deep, and decreases relatively little in depth towards 
its posterior end. The anterior two-thirds is straight and the posterior third gently 
down-flexed. The denticles tend to increase in size posteriorly, the most posterior 
