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STEATIGEAPHICAL GEOLOGY 



Echinoderma. Palaechinus Phillips! (but none are common). 



Crustacea. Illaenus femulus, Phaoops Weaveri, Ph. elegans. 



EracMopoda. Lingula crumena, Atrypa hemispherica, Meristella 



crassa, M. angustifrons, Stricklandia lens, Penta- 

 merus oblongus, P. undatus, Orthis reversa. 



Lamellibranchia. Ctenodonta Eastnori, Orthonota amygdalina, and 0. 

 inornata (both range into Wenlock). 



Pig. 49. GROUP OF WENLOCK FOSSILS. 



n. Lepadocrinus quadrifasciatus. 



b. Periechocrinus moniliformis. 



c. Calymene Blumenbaclii. 



d. Pliacops caudatus. 

 R. Bellerophon dilatatus. 

 /. Orthoceras annulatuiu. 



Gastropoda. Turbo tritorquatus, Holopella cancellata, Omphalo- 



trochus prenuntius. 

 Cephalopoda. Tretoceras bisiphonatum, Cyrtoceras approximatum, 



Orthoceras conicum. 



Fossils of the Wenlock Series 



Hydrozoa. (See table of graptolite zones. ) 



Actinozoa. Acervularia luxurians, Arachnophyllum Murchisoni, 



A. typus, Strombodes diffluens, Cyathophyllum 

 truncatum, Omyphyma turbinatum, Heliolites in- 

 terstinctus (from Bala), Favosites gottlandicus. 



