BRITISH AVONIAN CONODONT FAUNAS 37 
plumulus shirleyae subsp. nov.—oral view. 5a. Clydagnathus gilwernensis gen. et sp. 
nov.—oral view. 5b. Clydagnathus gilwernensis gen. et sp. nov.—lateral view. 
Siphonodella—Polygnathus imornatus Assemblage Zone. 6a. Polygnathus inornatus 
imornatus—lateral view. 6b. Polygnathus inornatus imornatus—oral view. 7a. Poly- 
gnathus lobatus lobatus—oral view. 8. Polygnathus lobatus inflexus—oral view. 9a. Poly- 
gnathus inornatus vostvatus—oral view. 9b. Polygnathus inornatus rostvatus—aboral view. 
toa. Siphonodella isosticha—aboral view. to0b. Siphonodella isosticha—oral view. 
Spathognathodus cf. robustus—S. tridentatus Assemblage Zone. 11. Spathognathodus 
cf. vobustus—lateral view. 12. Spathognathodus elongatus—lateral view. 13a. Spatho- 
gnathodus tridentatus—lateral view. 13b. Spathognathodus tridentatus—oral view. 
13c. Spathognathodus tridentatus—aboral view. 14. Spathognathodus crassidentatus— 
lateral view. 15. Spathognathodus anteposicornis—iateral view. 
Spathognathodus costatus costatus—Gnathodus delicatus Assemblage Zone. 16a. Spatho- 
gnathodus costatus costatus—lateral view. 16b. Spathognathodus costatus costatus—aboral 
view. 17a. Spathognathodus costatus sulciferus—lateral view. 17b. Spathognathodus 
costatus sulciferus—oral, view. 18a. Spathognathodus cf. cristulus—lateral view. 
18b. Spathognathodus cf. cristulus—oral view. 19. Spathognathodus cf. cyvius—lateral 
view. 20a. Gnathodus delicatus—lateral view. 20b. Gnathodus delicatus—oral view. 
21. Ligonodina beata nom. nov.—inner lateral view. 22. Hindeodella corpulenta—lateral 
view. 23. Hindeodella subtilis—-lateral view. 24a. Pseudopolygnathus primus—oral 
view. 24b. Pseudopolygnathus primus—aboral view. 25. Pseudopolygnathus cf. 
dentilineatus—oral view. 26a. Pseudopolygnathus multistvriatus—aboral view. 26b. 
Pseudopolygnathus multistvriatus—oral view. 27. Gnathodus simplicatus sp. nov.—oral 
view. 28a. Clydagnathus unicornis gen. et sp. nov.—oral view. 28b. Clydagnathus 
unicornis gen. et sp. nov.—lateral view. 29a. Pseudopolygnathus postinodosus sp. nov.— 
oral view. 29b. Pseudopolygnathus postinodosus sp. nov.—lateral view. 
Polygnathus lacinatus Assemblage Zone. 30. Polygnathus lacinatus lacinatus—oral 
view. 31a. Polygnathus lacinatus asymmetricus subsp. nov.—lateral view. 31b. Poly- 
gnathus lacinatus asymmetricus subsp. nov.—oral view. 32. Polygnathus nodomarginatus— 
oral view. 33a. Cavusgnathus sp. nov. A.—oral view. 33b. Cavusgnathus sp. nov. 
A.—lateral view. 34. Pseudopolygnathus multistriatus—oral view. 
Polygnathus lacinatus—Pseudopolygnathus cf. P. longiposticus Assemblage Zone. 
35. Gnathodus semiglabey—oral view. 36a. Gnathodus delicatus—lateral view. 36b. 
Gnathodus delicatus—oral view. 37. P. cf. longiposticus—lateral view. 38. Polygnathus 
lacinatus lacinatus—oral view. 39a. Spathognathodus pulcher—oral view. 39b. Spatho- 
gnathodus pulcher—lateral view. 40. Gnathodus simplicatus sp. nov.—oral view. 4Ia. 
Gnathodus avonensis sp. nov.—oral view. 41b. Gnathodus avonensis sp. nov.—lateral 
view. 
Gnathodus antetexanus—Polygnathus lacinatus Assemblage Zone. 42. Apatognathus 
geminus—inner lateral view. 43. Apatognathus scalenus—inner lateral view. 44. 
Apatognathus petilus—outer lateral view. 45a. Spathognathodus cf. cristulus—lateral 
view. 45b. Spathognathodus cf. cristulus—oral view. 46. Gnathodus antetexanus—oral 
view. 
Mestognathus beckmanni—Polygnathus bischoffi Assemblage Zone. 47a. Mestognathus 
beckmanni—iateral view. 47b. Mestognathus beckmanni—oral view. 48a. Polygnathus 
bischoffi sp. nov.—oral view. 48b. Polygnathus bischoffi sp. nov.—aboral view. 
Cavusgnathus unicornis—A patognathus Assemblage Zone. 49. Cavusgnathus unicornis 
—inner lateral view. 50a. Spathognathodus cristulus—iateral view. 5o0b. Spathognatho- 
dus cyristulus—oral view. 51a. Mestognathus beckmanni—inner lateral view. 51b. 
Mestognathus beckmanni—oral view. 52a. Gnathodus cuneiformis—oral view. 52b. 
Gnathodus cuneiformis—lateral view. 53a. Cavusgnathus chavactus—oral view. 53b. 
[Caption to Fig. 13 continued on p. 38 
