A Monograph of the British Fossil Cephalopoda |
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Page 31
... sutures . The sutures form plane curves only in uncoiled shells , and even in these they are more commonly concave towards the aperture . If the concavity does not extend from one side to the other , they are called undulating , because ...
... sutures . The sutures form plane curves only in uncoiled shells , and even in these they are more commonly concave towards the aperture . If the concavity does not extend from one side to the other , they are called undulating , because ...
Page 32
... sutures has a totally different origin from those large ones which characterise the Ammonitoidea , and must not be confounded with them . As to the lobe on the ventral side , it is only found in those species with a ventral siphuncle ...
... sutures has a totally different origin from those large ones which characterise the Ammonitoidea , and must not be confounded with them . As to the lobe on the ventral side , it is only found in those species with a ventral siphuncle ...
Page 42
... sutures ; 3. The involution of the shell ; 4. The form of the aperture ; 5. The symmetry or asymmetry of the shell ; 6. The direction of the neck of the septa ; 7. The simplicity or complication of the siphuncle . According as one or ...
... sutures ; 3. The involution of the shell ; 4. The form of the aperture ; 5. The symmetry or asymmetry of the shell ; 6. The direction of the neck of the septa ; 7. The simplicity or complication of the siphuncle . According as one or ...
Page 44
... sutures , are nearest among Nautiloids to the Ammonites . Indeed , in the matter of sutures these two genera overlap , and they must necessarily , therefore , be closely allied . They are , however , sharply distinguished by the ...
... sutures , are nearest among Nautiloids to the Ammonites . Indeed , in the matter of sutures these two genera overlap , and they must necessarily , therefore , be closely allied . They are , however , sharply distinguished by the ...
Page 45
... sutures are complex , never entirely without lobes , the more acute parts pointing from the aperture . Since , with the single exception of a possible Goniatite , the whole of the Silurian Cephalopoda belong to the first suborder , the ...
... sutures are complex , never entirely without lobes , the more acute parts pointing from the aperture . Since , with the single exception of a possible Goniatite , the whole of the Silurian Cephalopoda belong to the first suborder , the ...
Other editions - View all
A Monograph Of The British Fossil Cephalopoda J F (John Frederick) 1839-1 Blake No preview available - 2023 |
A Monograph Of The British Fossil Cephalopoda J F (John Frederick) 1839-1 Blake No preview available - 2023 |
Common terms and phrases
Actinoceras annulatum aperture appears Aymestry Bala Beds Bala Series Barrande basal diameter body-chamber Bohême British Builth Carboniferous central Cephalopods chamber characters cicatrix circular collection of Dr compressed concave Coniston convex side convexity curve CYRTOCERAS Description.-The Desertcreat distance Distribution.-In dorsal Dudley elliptic Endoceras examples figured flattened Foss Fossils genus Geol GOMPHOCERAS greatest diameter Grindrod ibex imbrications inches last whorl layer Ledbury Leintwardine lines of growth Lituites Llandeilo Llandovery long diameter Lower Ludlow Lower Silurian Ludlow of Ledbury M'Coy Museum of Practical Nautiloidea Nautiloids Nautilus nearly oblique ornaments ORTHOCERAS Orthocerata Phragmoceras Portlock Practical Geology rate of increase ratio riblets ribs Salter seen septa septa are direct septal surface septum Shale shell sigmoid Silur Silurian rocks siphuncle slightly Sowerby in Murchison's species specimen sutures Syst transverse Trochoceras Type.-The section undulating Upper Llandovery Upper Ludlow Upper Silurian ventral side Wenlock Limestone Wenlock Shale whorl Woodwardian Museum
Popular passages
Page 69 - PORTLOCK.- REPORT ON THE GEOLOGY OF THE COUNTY of LONDONDERRY, and of Parts of Tyrone and Fermanagh, examined and described under the Authority of the Master-General and Board of Ordnance. By JE PORTLOCK, FRS &c.
Page 77 - FREDERICK M°CoY, FGS One vol., Royal 410. Plates, /i. is. A CATALOGUE OF THE COLLECTION OF CAMBRIAN AND SILURIAN FOSSILS contained in the Geological Museum of the University of Cambridge, by JW SALTER, FGS With a Portrait of PROFESSOR SEDGWICK.
Page 78 - On the Succession of the Ancient Rocks in the vicinity of St. David's, Pembrokeshire, with special reference to those of the Arenig and Llandeilo Groups, and their Fossil Contents,
Page 77 - Silnrians. p. 170 -174.) On the tripartite classification of the Lower Palaeozoic Rocks, in: Geol. Mag. N. Ser. Dec. II. Vol. VI. 1879. p. 1—15. (Dnrch die fossile Fauna bestimmt.) and J. Wilson, On the Silurian Rocks of the Counties of Roxburgh and Selkirk.
Page 75 - On the Break between the Upper and Lower Silurian Rocks of the Lake District, as seen between Kirkby Lonsdale and Malham, near Settle, in : Geol.
Page 140 - ... connects it with O. semicircularis, Eichw. and O. carinata, Conrad, Ann. Rep. 1839, p. 64. Nevertheless I do not feel sure that this may not ultimately prove a variety of O. callactis, Dalm., a species which unfortunately has never been published with sufficient detail. ORTHOCERAS VAGANS, Salter, MSS. Smooth ; long tapering when young, more conical when old : septa broad elliptical, oblique on the longer axis, moderately distant in the young shell, distant by more than the diameter in mid-age,...
Page 74 - ... Quart. Journ. Sc. Vol. 3. 1863. p. 178—179. Note on the Fossils [of part of the Counties of Cork and Kerry.] in : Explanations to accompany sheet 197 and 198, and the south east part of 191, of the maps of the Geol. Survey of Ireland. Dublin, 1860.
Page 75 - and " Bala limestones," near Oswestry. (ditto), 343-7. 4. Denudation, unconformability, and the Vale of Clwyd. (ditto), 476-8. 5. List of fossils described from the Bala limestone and its associated beds of North Wales. Liverpool Geol. Soc. Proc., vi, 1865, 30-4.
Page 105 - On the surface of these caps the deeper furrows lie on the side nearest to the siphuncle ; they are generally median, but occasionally paired ; on the other side are three or more lighter furrows, which occasionally bifurcate. It is difficult to conjecture the cause of these phenomena, which must have had their origin between the formation of one septum and the next. I can only...
Page 71 - ... rocks, and in which, in its published form, the first Scottish Maclurea was figured and described, though somewhat doubtfully, from the imperfect state of keeping of the specimen, and under another name. At the meeting of the British Association held in this city in 1850, Professor Sedgwick read a paper on the Geological Structure and Relations of the Frontier Chain of Scotland...