ZONE OF AEGOCERAS HENLEYI. 



ECHINODERMATA. 



Cidaris Edwardsii, Wright. 

 Rabdocidaris Moraldina, CoU. 

 Hemipedina Jardiuii, Wright. 

 Uraster Gaveyi, Forb. 

 Tropidaster pectinatus, Forb. 



Ophioderma Gaveyi, Wrt. 



— Brodiei, Wrt. 

 Pentacrinus robustus, Wrt. 



— punctiferus, Quenst. 



— subangularis, Mill. 



In Dorsetshire this zone occupies a conspicuous position in the cliff sections, as at 

 Black Ven, Stoiiebarrow Hill, Westhay Cliff, and at the Golden Cap, all of which 

 exhibit profiles of the beds, Mr. E. C. H. Day, E.G.S.,^ has given an exhaustive 

 description of these in his excellent memoir ; and, as I had the pleasure of working over 

 some of the sections with my friend, I select that at the Golden Cap as the most typical 

 for a general view of the whole. The lower portion of this headland consists of — 



I. The Upper Marls, without mica, of De la Beche's section, in which a greater 

 number of Belemnites are found than in any other division of the Lias ; seams of grey 

 marls full of these fossils are seen along the shore at low tide. Belemnites longissimus. 

 Mill., B. elongatus. Mill., and B. clavatus, Schloth., appear to be the prevailing forms. 

 Here, likewise, are found Lytoceras fimbriatum, Aeg. Bechei, Acg. Henleyi, Aeg. 

 striatum, Phglloceras Loscovibi, Nautilus semistriatus, d'Orb., Nautilus inornatus, Trochus 

 imbricatus, Eucydus Gaudryanus, CJiemnitzia Periniana, Pleurotomaria similis, Cryptania 

 expansa, Inoceramus ventricosus, Hinnites tumidus, Plicatula spinosa, Pecten sp. 



II. The next strata in ascending order are known to local collectors as the " Gi'een 

 Ammonite-beds,'' as they afford a rich harvest of fossils, which are well preserved in the 

 greenish non-micaceous marls that constitute this stage. It was in these I found 

 the specimens of Aegoceras Henleyi, which have enabled me to demonstrate the remarkable 

 history of this species, so long misunderstood by palaeontologists, and Aegoceras Davoei, 

 the rarest Cephalopod in the locality, associated with Aeg. Bechei and Monotis 

 inaquivalvis in the same small slab. 



Fossils of the Green Ammonite-beds, near Charmouth. 



Ichthyosaurus. 

 Plesiosaurus. 

 Aegoceras Heuleyi, Sow. 

 Bechei, Sow. 



— striatum, Reinecke. 



— Davoei, Sow. 

 Lytoceras fimbriatum, Sow. 

 Phylloceras Loscombi, Sow. 



Nautilus semistriatus, (TOrb. 

 Belemnites longissimus, Mill. 

 — compressus, Stahl. 

 Cryptsenia expansa, Sow. 

 Chemnitzia Carucensis, d'Orb. 

 Pterocera liasina, d'Orb. 

 Inoceramus ventricosus, Sow. 

 Monotis iusequivalvis, Sow. 



^ "The Middle and Upper Lias of the Dorsetshire Coast," 'Quart. Journ. Geol. Soc.,' vol. xix , 

 p. 278, 1863. 



3 Ibid., p. 283. 



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