ZONE OY HARPOCERAS BIFRONS. 



129 



Annelida. 



Serpula gordialis, Schloth. 



— Umax, Gold/. 



— tricristata, Gold/. 



Rhabdocidaris impar, Dumort. 

 Cidaris Dumortieri, Wright. 



Serpula ramentum, Dumort. 



— segmentata, Dumort. 



— lumbricalis, Schloth. 



ECHINODERMATA. 



Pentacrinus jurensis, Quenst. 

 Millericrinus Hausrnanni, Rom. 



Chondrites Bollensis, Kurr. 



The fragments obtained from washing the bottom clay at Bloxam contained the remains of Ophiuridae 

 with the plates and spines of several species of Echinidse. 



Crustacea. 



Bairdia, sp. 



Cristellaria Bronni, JLiim. 

 • — cultrata, Montf. 



— antiquata, d'Orb. 



— matutina, d'Orb. 



— rhomboidea, Czjek. 



— rotulata, Lam. 



— recta, d'Orb. 



— varians, Born. 

 Dentalina Burgundiae, Terq^. 



— communis, d'Orb. 



— filiformis, d'Orb. 



— nummulina, Giimb. 



Cythere, sp. 



EoRAMINIPERA. 



Dentalina obscura, Terq. 



— ornata, Terq. 



— pauperata, d'Orb. 



— quadricostata, Terq. 

 Flabellina rugosa, d'Orb. 

 Nodosaria raphanistrum, Terq. 



— Badenensis, d'Orb. 

 Planularia harpula, d'Orb. 



— pauperata, /. ^ P. 



— reticulata, Cornell. 

 Lingulina tenera, Born. 

 Vaginulina striata, d'Orb. 



In Rutland the Serpentimm and Bifrons zones approach so close together that then- 

 fossils in many cases cannot be separated. The Serpentinum-zonc, with its " Fish-bed and 

 Insect limestone," appears to be the one most fully developed in this county. 



In North- West Lincolnshire the Rev. J. E. Cross, F.G.S.,^ has noted the Upper 

 Lias in the Santon Railway-cutting, and collected therefrom Harpoceras serpentinum, 

 Stephanoceras commune, Lytoceras cornucopia^ and Amaltheus spinatus. 



Foreign Correlations. — The Upper Lias in South-west Germany was divided by 

 Professor Quenstedt^ into Posidonienscldefer and Jurensis-Mergel ; the former corre- 

 sponding to the Serpentinum and Bifrons zones, and the latter to the Jurense and Opalinum 

 zones of this work. The " Poisidonienschiefer" are characterised by the presence of 

 Fish, as Ptycholepis Bollensis, Euf/natJius, Tetragonolepis, Pholidotus semicinctus, Lepi- 

 dotus Elvensis, semiserratus, dentatus, Semionotus leptocephalus, Aspidorynchus, Bachy- 



1 'Quart. Journ. Geol. Soc.,' vol. xxi, p. 124, 187j, 



2 Tlozgebirge WUrtembergs,' p. 539, 1843. 



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