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TREPOSTOME IDENTIFICATION KEY 



In order to identify trepostome bryozoans from Clog-y-fran thin 

 sections are needed. Ideally at least two oriented sections (longitudi- 

 nal and tangential) are required. However, specimens can sometimes 

 be identified from randomly oriented sections. Identification can be 

 hindered when specimens are fragmented and abraded. The key 

 aims to aid identification, but results should be carefully checked 

 against the complete descriptions and the illustrations of the species. 



1. Zoaiia inassive and hemispherical 2 



Zoaria erect 3 



2. Ring diaphragms present Hemiphragma sp 



Ring diaphragms and mesozooecia absent Monotrypa sp 



3. Hemiphragms present 4 



Hemiphragms absent 5 



4. Mesozooecia abundant with numerous diaphragms along their length 



Dittopora sanclerensis 



Mesozooecia present, but not common Hemiphragma pygmaeum 



5. Cystiphragms present 6 



Cystiphragms absent 7 



6. Abundant acanthostyles present Monticulipora aff. compacta 



Small indistinct acanthostyles present Homotrypa cf. similis 



I . Acanthostyles present 8 



Acanthostyles absent 15 



8. Diaphragms rare in autozooecia 9 



Diaphragms abundant in autozooecia 12 



9. Mesozooecia! walls constricted at the position of the diaphragms pro- 

 ducing a beaded appearance Hetrotrypa sp 



Mesozooecial walls straight in appearance 10 



10. Branches >3 mm in diameter 1 1 



Branches <3 mm in diameter Leioclema sp. B 



I I . Acanthostyles composed of broad hyaline core with no sheathing 



laminae Leioclema^ sp. 



Acanthostyles composed of broad hyaline core surrounded by steeply 

 dipping conical laminae Leioclema sp. A 



12. Autozooecial basal diaphragms very abundant and regularly spaced 



throughout colony Amplexopora sp. 



Autozooecial basal diaphragms present throughout colony but more 

 abundant in the exozone 13 



13. Meandering autozooecia roughly parallel to branch axis in endozone 

 then curving very slightly to meet zoarial surface 



Eridotrypa simulatrix 



Straight autozooecia roughly parallel to branch axis in endozone curve 

 to meet zoarial surface 14 



14. Thick exozonal walls with abundant diaphragms 



Batostoma cf. polare 



Otherwise Batostoma clogyfranense 



15. Mesozooecia present 16 



Mesozooecia absent, exilazooecia present . Halloporina cf. crenulata 



16. Mesozooecia beaded in appearence Hallopora peculiaris 



Mesozooecia straight-walled Hallopora aff. wesenbergiania 



